is anyone willing to help with some exam questions?

Watch
izziw19
Badges: 10
Rep:
?
#1
Report Thread starter 1 month ago
#1
Hi, i am really struggling with some maths questions. I dont wish to be ridiculed or mocked because i really am struggling and mocking me wont help matters.
0
reply
izziw19
Badges: 10
Rep:
?
#2
Report Thread starter 1 month ago
#2
Name:  2021-03-04 (7).png
Views: 11
Size:  74.7 KB
0
reply
braindeadpog
Badges: 8
Rep:
?
#3
Report 1 month ago
#3
(Original post by izziw19)
Name:  2021-03-04 (7).png
Views: 11
Size:  74.7 KB
work through the (2x+1)(3x+2) and then work through the x(3x+5) and then you'll be left with terms which you can collect and add together
then with the perfect square uhh lets say you have an equation like this:
ax^2 + bx + c
for it to be a perfect square half of b squared should be c
so one example would be:
x^2 + 6x + 9
(half of 6 is 3 and 3 squared is 9 which is in fact the third number and so its a perfect square)
i mean that's the easy way to explain it and i think you'll get a mark for proving it like that but if you want to get all technical then whatever values you have should satisfy b^2 = 4ac
0
reply
IReallyDoNotKnow
Badges: 10
Rep:
?
#4
Report 1 month ago
#4
Expand all the brackets and simplify (remember foil) and you will be left with a quadratic expression. You should be able to factorise this quadratic, (using ac method since the coefficient of x^2 is bigger than 1). The factorised form can be written as a square, hence showing it is a perfect square.

Alternatively, expand all brackets and simplify. Then factorise 9 from the x^2 and x terms, and complete the square. After simplifying the terms, you will note it to be in the form of 9(x+c)^2. Since 9 = 3^2. Think about what happens when two squares are multiplied together ( e.g. m^2 x n^2, can be writtern as m x m x n x n , or mn x mn, which simplifiers to mn ^2)

In terms on how to improve in such questions, revisit quadratic factorisation, expanding and simplifying brackets + algebraic proofs
Last edited by IReallyDoNotKnow; 1 month ago
0
reply
old_engineer
Badges: 11
Rep:
?
#5
Report 1 month ago
#5
(Original post by izziw19)
Hi, i am really struggling with some maths questions. I dont wish to be ridiculed or mocked because i really am struggling and mocking me wont help matters.
As braindeadpog has said, you can approach this question by multiplying out all the brackets, grouping the resulting terms into a single quadratic and then showing that the quadratic has two identical factors. But there is another way. You could note that 3x + 5 = 3x + 2 + 3, meaning that the x(3x + 5) term can be rewritten as x(3x + 2) + 3x. The complete expression should then consist of three terms, all of which have the factor (3x + 2). This give you another way forward.
0
reply
izziw19
Badges: 10
Rep:
?
#6
Report Thread starter 1 month ago
#6
Thankyou so much for your help

(Original post by old_engineer)
As braindeadpog has said, you can approach this question by multiplying out all the brackets, grouping the resulting terms into a single quadratic and then showing that the quadratic has two identical factors. But there is another way. You could note that 3x + 5 = 3x + 2 + 3, meaning that the x(3x + 5) term can be rewritten as x(3x + 2) + 3x. The complete expression should then consist of three terms, all of which have the factor (3x + 2). This give you another way forward.
0
reply
izziw19
Badges: 10
Rep:
?
#7
Report Thread starter 1 month ago
#7
(Original post by IReallyDoNotKnow)
Expand all the brackets and simplify (remember foil) and you will be left with a quadratic expression. You should be able to factorise this quadratic, (using ac method since the coefficient of x^2 is bigger than 1). The factorised form can be written as a square, hence showing it is a perfect square.

Alternatively, expand all brackets and simplify. Then factorise 9 from the x^2 and x terms, and complete the square. After simplifying the terms, you will note it to be in the form of 9(x+c)^2. Since 9 = 3^2. Think about what happens when two squares are multiplied together ( e.g. m^2 x n^2, can be writtern as m x m x n x n , or mn x mn, which simplifiers to mn ^2)

In terms on how to improve in such questions, revisit quadratic factorisation, expanding and simplifying brackets + algebraic proofs
Thank you so much! You are a star!
0
reply
izziw19
Badges: 10
Rep:
?
#8
Report Thread starter 1 month ago
#8
Name:  2021-03-04 (12).png
Views: 11
Size:  124.6 KB

any ideas??
0
reply
Muttley79
Badges: 20
Rep:
?
#9
Report 1 month ago
#9
(Original post by izziw19)
Name:  2021-03-04 (12).png
Views: 11
Size:  124.6 KB

any ideas??
What are yours? We cannot do questions for you as it's against the rules/
0
reply
izziw19
Badges: 10
Rep:
?
#10
Report Thread starter 1 month ago
#10
(Original post by braindeadpog)
work through the (2x+1)(3x+2) and then work through the x(3x+5) and then you'll be left with terms which you can collect and add together
then with the perfect square uhh lets say you have an equation like this:
ax^2 + bx + c
for it to be a perfect square half of b squared should be c
so one example would be:
x^2 + 6x + 9
(half of 6 is 3 and 3 squared is 9 which is in fact the third number and so its a perfect square)
i mean that's the easy way to explain it and i think you'll get a mark for proving it like that but if you want to get all technical then whatever values you have should satisfy b^2 = 4ac
i got this way of doing it
6x^2+7x+2
ax^2+bx+c
a=6
b=7
c=2
to be a perf square should be b^2=4ac
7^2=4x6x2
which equals 48 so would it be equal or not?
0
reply
izziw19
Badges: 10
Rep:
?
#11
Report Thread starter 1 month ago
#11
(Original post by Muttley79)
What are yours? We cannot do questions for you as it's against the rules/
i am not asking for ANSWERS. i am asking for help. smhhhh
0
reply
Muttley79
Badges: 20
Rep:
?
#12
Report 1 month ago
#12
(Original post by izziw19)
i am not asking for ANSWERS. i am asking for help. smhhhh
You need to give a starting point as that's the key ... how could you use algebra to express the ratio? For all we know this could be an assessment
0
reply
Muttley79
Badges: 20
Rep:
?
#13
Report 1 month ago
#13
(Original post by izziw19)
i got this way of doing it
6x^2+7x+2
ax^2+bx+c
a=6
b=7
c=2
to be a perf square should be b^2=4ac
7^2=4x6x2
which equals 48 so would it be equal or not?
Check expanding - not what I got.
0
reply
abbiieo
Badges: 9
Rep:
?
#14
Report 1 month ago
#14
Hey, I think this video might help. https://www.tiktok.com/@gcsemathstok...77589564605958
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

What factors affect your mental health the most right now?

Anxiousness about lockdown easing (147)
4.89%
Uncertainty around my education (443)
14.73%
Uncertainty around my future career prospects (338)
11.24%
Lack of purpose or motivation (419)
13.93%
Lack of support system (eg. teachers, counsellors, delays in care) (140)
4.66%
Impact of lockdown on physical health (181)
6.02%
Loneliness (258)
8.58%
Financial worries (109)
3.62%
Concern about myself or my loves ones getting/having been ill (123)
4.09%
Exposure to negative news/social media (136)
4.52%
Lack of real life entertainment (163)
5.42%
Lack of confidence in making big life decisions (266)
8.85%
Worry about missed opportunities during the pandemic (284)
9.44%

Watched Threads

View All
Latest
My Feed