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2 votes
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2x-3y=7

-3x +7y = - 8

4x-3y = 9
2x + 3y = 9

SOLVE BOTH EQUATIONS??

User Rikin Thakkar
by
3.0k points

1 Answer

25 votes
25 votes

Answer:

(5, 1 ) and (3, 1 )

Explanation:

2x - 3y = 7 → (1)

- 3x + 7y = - 8 → (2)

multiplying (1) by 3 and (2) by 2 and adding will eliminate x

6x - 9y = 21 → (3)

- 6x + 14y = - 16 → (4)

add (3) and (4) term by term to eliminate x

0 + 5y = 5

5y = 5 ( divide both sides by 5 )

y = 1

substitute y = 1 into either of the 2 equations and solve for x

substituting into (1)

2x - 3(1) = 7

2x - 3 = 7 ( add 3 to both sides )

2x = 10 ( divide both sides by 2 )

x = 5

solution is (5, 1 )

------------------------------------------------------------

4x - 3y = 9 → (1)

2x + 3y = 9 → (2)

adding the 2 equations term by term will eliminate y

6x + 0 = 18

6x = 18 ( divide both sides by 6 )

x = 3

substitute x = 3 into either of the 2 equations and solve for y

substituting into (2)

2(3) + 3y = 9

6 + 3y = 9 ( subtract 6 from both sides )

3y = 3 ( divide both sides by 3 )

y = 1

solution is (3, 1 )

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