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Which of the following are solutions to 2x^2-8x-90? select all that apply.
10 months ago
Q:
Which of the following are solutions to 2x^2-8x-90? select all that apply.
Accepted Solution
A:
Simplifying:
2x2 + -8x + -90 = 0
Reorder the terms:
-90 + -8x + 2x2 = 0
Solving
-90 + -8x + 2x2 = 0
Solving for variable 'x'.
Factor out the Greatest Common Factor (GCF), '2'.
2(-45 + -4x + x2) = 0
Factor a trinomial.
2((-5 + -1x)(9 + -1x)) = 0
Ignore the factor 2.
Subproblem 1:
Set the factor '(-5 + -1x)' equal to zero and attempt to solve:
Simplifying
-5 + -1x = 0
Solving
-5 + -1x = 0
Move all terms containing x to the left, all other terms to the right.
Add '5' to each side of the equation.
-5 + 5 + -1x = 0 + 5
Combine like terms:
-5 + 5 = 0 0 + -1x = 0 + 5 -1x = 0 + 5
Combine like terms:
0 + 5 = 5 -1x = 5
Divide each side by '-1'.
x = -5
Simplifying
x = -5
Subproblem 2:
Set the factor '(9 + -1x)' equal to zero and attempt to solve:
Simplifying
9 + -1x = 0
Solving
9 + -1x = 0
Move all terms containing x to the left, all other terms to the right.
Add '-9' to each side of the equation.
9 + -9 + -1x = 0 + -9
Combine like terms:
9 + -9 = 0 0 + -1x = 0 + -9 -1x = 0 + -9
Combine like terms:
0 + -9 = -9 -1x = -9
Divide each side by '-1'.
x = 9
Simplifying x = 9
Solution
x = {-5, 9}