Question

X2 + 14 = 18
A) 5,-5
B) 4,-4
C) 2,-2

Answer 1

answer should be 2

Explanation:

2^2+14=18

Answer 2

C) 2, -2

Explanation:

When you subtract 14 from both sides of the equation, you are left with ...

x^2 = 4

Taking the square root of both sides gives ...

x = ±√4 = ±2

Solutions are x = 2, x = -2.

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Alternate solution

Subtract 18 from both sides of the equation.

x^2 -4 = 0

(x -2)(x +2) = 0 . . . . . factor the differenc x = 2, x = -2e of squares

. . . . . . values of x that make the factors zero

The zero product rule tells you the product is only zero if one or more of the factors is zero.