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5 votes
QUESTION FOR 50 POINTS

Solve this equation using an algebraic method: (x + 4)(x - 4) = 9
Choices are:
x=5
x=4 and x=-4
x=9
x=5 and x=-5

User Toxalot
by
8.6k points

2 Answers

1 vote
the answer is
x=5 and x=-5
User Eavidan
by
8.2k points
3 votes
(x+4)(x-4)=9 expand left side by performing indicated multiplication...

x^2-16=9 add 16 to both sides

x^2=25 take the square root of both sides...

x=±5

x=-5 and 5

So the answer would be the bottom choice.
User JShorthouse
by
8.2k points

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