Question

Solve the equation using square roots. 3x2 – 27 = 0

A. no real number solutions
B. Plus or minus 9.
C. Plus or minus 3.
D. 3

Answer 1

C. Plus or minus 3

Explanation:

Take a GCF of 3 out of both terms in the binomial. You'll get 3*(x^2-9)=0. Then use FOIL to get the binomials (x+3) and (x-3). You're answers will be -3 and 3

Answer 2

C, Plus or minus 3

Explanation:

to solve 3x² - 27 = 0, we want to get the x by itself, so lets add 27 to both sides.

3x² = 27 < divide both sides by 3 to get x alone

3x²/2 =x²

27/3 = 9

x² = 9 < we can use the square-root property and square both sides of the equation to get x alone. we use the ± because there are 2 possible solutions to a square rooted number

√x² = x

√9 = 3

x = ±3

looking at our answer choices, the correct answer is C