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Solve the system by the elimination method.

R - 9S = 2
3R - 3S = -10

A. {(-4, -8/3)}
B. {(-4, -3/2)}
C. {(-4, -2/3)}

User Shuckc
by
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1 Answer

4 votes

C. (-4,-⅔)

Explanation:

Elimination Method:

R - 9S = 2

3R - 3S = -10

I'll solve for X first by eliminating S.

R - 9S = 2

-3(3R - 3S = -10)

R - 9S = 2

-9R + 9S = 30

(Add the equations)

-9R = 32

(Divide both sides by -9)

-9R/-5 = 32/-5

R = -4

Substitute the R value into either equation:

R - 9S = 2

(-4) - 9S = 2 (Add 4 to both sides of the equation)

+4 +4

-9S = 6 (Divide both sides of the equation by -9)

-9S/-9 = 6/-9

S = -6/9

Simplify

S = -2/3

Solution: (-4,-⅔)

Hope this helped

User Deech
by
7.2k points