You area told that y is proportional to x2 and that when y = 75, x = 5. a) Find a formula for y in terms of x. b) Find the value of y when x = 3. c) Find the value of x when y = 1200.

a) when y=75 x=5 and y is proportional to x^2, so the answer is y=___x^2
if x=5, then x^2 = 25, and 75/25=3, so the answer is y=3x^2

b) if x=3, x^2=9, if you multiply this by 3, you get the answer of 27.

c)if y=1200, 1200 divided by 3 is 400, and the square root of 400 is 20. So the answer is 20.

Answered by Millie B. Maths tutor

3053 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

multiply out (2x-4)(x-2) and simplify.


Anne picks a 4-digit number. The first digit is not zero. The 4-digit number is a multiple of 5. How many different 4-digit numbers could she pick?


How do I solve a simultaneous equation?


Solve x^3+20x^2=125x


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences