Question

What are the solution(s) to the quadratic equation x2 – 25 = 0?

O x = 5 and x = -5
OX=25 and x = -25
O x = 125 and x = -125
O no real solution​

Answer 1

x = ± 5

Explanation:

Given

x² - 25 = 0

There are 2 possible approaches to solving this equation

Approach 1

add 25 to both sides

x² = 25 ( take the square root of both sides )

x = ±
`√(25)` = ± 5

Approach 2

x² - 25 ← is a difference of squares and factors as

(x - 5)(x + 5) = 0 ← in standard form

Equate each factor to zero and solve for x

x - 5 = 0 ⇒ x = 5

x + 5 = 0 ⇒ x = 5

Answer 2

`x^2 - 25 = 0\\x^2=25\\x=-5 \vee x=5`