Let a = 4b + 5(c - b). Find the value of c when a = 8 and b = 7.

a = 4b + 5(c - b) - question8 = (4*7) + 5(c - 7) - insert values given in question8 = 28 + 5c -35 - multiply and expand brackets8 - 28 + 35 = 5c - take away 28 from the left and right-hand side of the equation. Add 35 to the left and right-hand side also15 = 5c - simplify15/5 = c - divide right hand side by constant on left hand side so the variable c is on its own3 = c - answer

GH

Related Maths GCSE answers

All answers ▸

Prove the square of an odd number is always 1 more than a multiple of 4


Show that ((sqrt(18)+sqrt(2))^2)/(sqrt(8)-2) can be written in the form a(b + 2) where a and b are integers.


Show that the two lines are parallel: L1: 4y = 24x +12, L2: 2y + 13 = 12x


I decrease a number by 26%, the answer is 9 x10^-7, what was the original number?