Question

What is the first step in solving the quadratic equation x2 – 40 = 0?

Answer 1

`x^2- 40 = 0\ \ \ \Leftrightarrow\ \ \ x^2-(2 √(10) )^2=0\\\\\ \ \ \Leftrightarrow\ \ \ (x-2 √(10) )(x+2 √(10) =0\\\\ \ \ \Leftrightarrow\ \ \ x=2 √(10) \ \ \ \ \ or\ \ \ \ \ x=-2 \sqrt{10`

Answer 2

Given the quadratic equation:
`x^2-40=0`

Addition property of equality states that you add the same number to both sides of an equation.

Step 1.

`x^2-40=0`

Add 40 to both sides of an equation:

`x^2-40+40=0+40`

Simplify:

`x^2=40` ......[1]

Step 2.

Take square root both sides in equation [1]; we have

`√(x^2) =√(40)`

Simplify:

`x=\pm √(40) =\pm 2√(5)`

Hence, the roots for the given equation is x =
`+2√(5)` ,
`-2√(5)` .

Therefore, for solving the quadratic equation the first step is; Adding 40 to both sides of an equation.