someone show me step by step how to solve these two questions

Watch this thread
nebbercracker
Badges: 1
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#1
Report Thread starter 6 years ago
#1
So these are two questions on a past paper I am stuck with. One is inverse proportion and the other is simultaneous equation. Please could someone explain step by step how to solve them ?

Inverse proportion

h is inversely proportional to the square of r
when r =5 , h=3.4
find the value of h when r=8

simultaneous equation

x(squared) + y(squared) = 9
x + y = 2

help with these questions will be much appreciated
0
reply
rede121
Badges: 8
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#2
Report 6 years ago
#2
Inverse proportion:
Attached files
0
reply
M.C. Math
Badges: 7
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#3
Report 6 years ago
#3
(Original post by nebbercracker)
So these are two questions on a past paper I am stuck with. One is inverse proportion and the other is simultaneous equation. Please could someone explain step by step how to solve them ?

Inverse proportion

h is inversely proportional to the square of r
when r =5 , h=3.4
find the value of h when r=8

simultaneous equation

x(squared) + y(squared) = 9
x + y = 2

help with these questions will be much appreciated
Simultaneous equation.
- Take the second equation: y=2-x. Substitute for y in the first equation.
x2 + (2-x)2 = 9
- Expand the brackets
x2+x2-4x+4=9
2x2-4x-5=0. Solve for x (i'd use the quadratic formula as it doesn't factorise, or if you prefer to 'complete the square', divide through by 2), then substitute each value of x into the second equation to find y.
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

How was the OCR A-level Geography Paper 1 exam for you?

Great! (9)
14.29%
Quite well (29)
46.03%
Not so good (16)
25.4%
Terrible! (9)
14.29%

Watched Threads

View All