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cant do this simple equation

X
----- + 8 = 13
2

The answer is 10 but I get 18.
I times both sides by 2 so X +8 =26
Take 8 both sides so X = 18.

What am I doing wrong?

Also this one
X
----- - 5 = 30
2

Answer is 40 but i get 35
(edited 9 years ago)
Original post by wartortle
X
----- + 8 = 13
2

The answer is 10 but I get 18.
I times both sides by 2 so X +8 =26
Take 8 both sides so X = 18.

What am I doing wrong?

Also this one
X
----- - 5 = 30
2

Answer is 40 but i get 35

You have to multiply everything by 2 to get rid of the denominator not just what is after the = sign
So you would get x+16=26

Do the same for the other one

Edit: The answer isn't 40 for the second one.
(edited 9 years ago)
Original post by wartortle
X
----- + 8 = 13
2

The answer is 10 but I get 18.
I times both sides by 2 so X +8 =26
Take 8 both sides so X = 18.

What am I doing wrong?

Also this one
X
----- - 5 = 30
2

Answer is 40 but i get 35

it's 2∗(x2+8)=2∗(13)2 * (\dfrac{x}{2}+8)=2 * (13)
(edited 9 years ago)
do the addition and subtraction before the multiplication and division, effectively reverse BIDMUS :smile:
so x/2 + 8 = 13
-8 from both sides
x/2 = 5
times both sides by 2
x = 10.
Original post by wartortle
X
----- + 8 = 13
2

The answer is 10 but I get 18.
I times both sides by 2 so X +8 =26
Take 8 both sides so X = 18.

What am I doing wrong?

Also this one
X
----- - 5 = 30
2

Answer is 40 but i get 35

for the second one it's 2∗(x2−5)=2∗(30)2*(\dfrac{x}{2}-5) = 2*(30) the answer should be 70.
Reply 5
Avatar for wartortle
wartortle
OP
14
Original post by mightyfrog2_10
it's 2∗(x2+8)=2∗(13)2 * (\dfrac{x}{2}+8)=2 * (13)

how do you type like that?
Original post by wartortle
how do you type like that?

it's quite easy you have to learn latex: http://www.thestudentroom.co.uk/wiki/LaTex
so for fraction: \frac or to make the fraction clear use \dfrac
for multiplication i should have used \times instead of * sorry :biggrin:
you need to start of with then write everything in the middle and end with (without spaces in the word tex here)

do you know how to solve the questions above?
(edited 9 years ago)
Reply 7
Avatar for wartortle
wartortle
OP
14
Original post by mightyfrog2_10
it's quite easy you have to learn latex: http://www.thestudentroom.co.uk/wiki/LaTex
so for fraction: \frac or to make the fraction clear use \dfrac
for multiplication i should have used \times instead of * sorry :biggrin:
you need to start of with then write everything in the middle and end with
(without spaces in the word tex here)

do you know how to solve the questions above?
Thank you.

Yes I have now completed the question, thank you.
Original post by wartortle
Thank you.

Yes I have now completed the question, thank you.

cool, no problem.

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