f(x) = 5 – x and g(x) = 3x + 7 (a) Simplify f(2x) + g(x – 1)
May look hard at first but once understood is simple.Question is asking to add two functions together.Firstly we begin by calculation f(2x) We know that f(x) = 5 – x, to find f(2x) we replace the x by 2xThis gives us f(2x) = 2 -2xNext we calculate g(x-1) this one is a little trickier but follows the same ideawe know that g(x) = 3x +7, to find g(x-1) we replace the x by (x-1)This gives us g(x-1) = 3(x-1) +7 We then expand the brackets to find g(x-1) = 3x-3 +7Therefore f(2x) + g(x-1) = 2-2x +3x-3+7= 9 + x
MB
Related Maths GCSE answers
All answers ▸Gavin, Harry and Isabel each earn the same salary. Gavin saves 28% of his salary. Harry spends 3/4 of his salary and saves the rest. The amount Isabel saves:The amount she spends=3:7. Who saves the most?
Solve these simultaneous equations. 2x + y = 18 x - y = 6
Jo wants to work out the solutions of x^2 + 3x – 5 = 0 She says, ‘‘The solutions cannot be worked out because x^2 + 3x – 5 does not factorise to (x + a)(x + b) where a and b are integers.’’ Is Jo correct?
Write x^2+4x-12 in the form (x+a)^2+b where 'a' and 'b' are constants to be determined.