Question

The only solution of the equation x2 + bx + 16 = 0 is x = 4. What is the value of b?

b = –16
b = –8
b = 8
b = 16

Answer 1

b equals negative 8. becasue 16 is too large

Answer 2

Option B is correct.

value of b = -8

Explanation:

Given the equation:
`x^2+bx+16= 0`

As per the condition: The only solution for the given equation is, x = 4.

Substitute this value of x =4 in given equation, to solve for b;

`(4)^2+b(4)+16= 0`

Simplify:

`16+4b+16= 0`

or

`32 + 4b= 0`

Subtract 32 on both sides, we get;

32 + 4b -32 = 0-32

Simplify:

4b = -32

Divide both sides by 4 we get;

b = -8

therefore, the value of b = -8