4x^2 + 8x + 3 can be written in the form a(x + b)^2 + c where a, b and c are whole numbers. Work out the values of a, b and c.

Factorise 4x2 + 8x + 3 = 4(x2 + 2x + 3/4) divide the coefficient of x by 2: 2/2=1 Now x2+2x = (x+1)2-12 = (x+1)2-1 Hence, 4((x+1)2-1+3/4) = 4(x+1)2-1 which is of the form a(x + b)2 + c So a=4, b=1, c=-1

DW

Related Maths GCSE answers

All answers ▸

if x^2 + 9x + 20 = 0, what are the possible values of x?


I set up a tent (assume it’s a regular triangular prism) of length 2.2m. The triangular face of the tent is an isosceles triangle. The two identical sides are both 1.4m long and have an angle of 34degrees between them. Work out the volume of the tent -3sf


(x - 3)(x + 4) = 0 Solve for x


solve (5 - x)/2 = 2x - 7 to find the value of x