Question

What’s the solution of the equation x2+bx+16=0 is x=4. What is the value of b

Answer 1

b = -8

Explanation:

In order to find the value of "b", use the fact that x=4 is a solution to the equation. Replace "x" with the value "4" and make the expression equal zero (since x=4 is a solution), and solve for b:

`y=x^2+bx+16\\0=(4)^2+b(4)+16\\0=16+4b+16\\0=32+4b\\-32=4b\\b=(-32)/(4) \\b=-8`

Therefore b must be equal to "-8" for x=4 be a solution to the equation.