Question

A rectangular picture measuring 4 in. by 8 in. is surrounded by a frame with uniform width x. Write a quadratic function in standard form to show the combined area of the picture and frame.

Answer 1

standard form is f(x)=ax²+bx+c

A=(x+4)*(x+8)
=x²+4x+8x+32
=x²+12x+32=f(x)