Question

Solve h2-42 = -h using the quadratic formula.

A) h = 0 or h = 7
B) h = -6 or h = 7
C) h = 6 or h= -7
D) h = -6 or h = -7​

Answer 1

Answer: Option C

h = 6 or h= -7

Explanation:

We have the expression

`h^2-42 = -h`

To solve add h on both sides of the equality

`h^2+h-42 = -h+h`

`h^2+h-42 = 0`

For an equation of the form
`ah^2 +bh +c` the quadratic formula is

`h=(-b \± √(b^2 -4ac))/(2a)`

In this case

`a = 1\\b= 1\\c =-42`

`h=(-1 \± √(1^2 -4(1)(-42)))/(2(1))`

`h_1=6`

`h_2=-7`

The answer is the option C