Please help
What value of b makes the trinomial below a perfect square?

X^2-bx+16

Step-by-step explanation:

Given trinomial:

It has two perfect squares  and a variable with negative coefficient.

It can be representing a:

If we substitute m with x and n with 4,  we'll get 2mn = 2*x*4 = 8x.

This gives us b = 8

step-by-step explanation:

x^2 -12x + 36 + y^2 = 36

x^2 + y^2 = 12x

r^2 = 12rcos(theta)

r = 12 cos(theta)