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34 votes
Help me please must use elimination

Help me please must use elimination-example-1
User MgSam
by
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1 Answer

17 votes
17 votes

Answer:

(1,2)

(3, -1)

Explanation:

2x + 5y = 12

4x -y = 2 Multiply this through by 5 and then add to the equation above

2ox - 5y = 10

2x + 5y = 12

22x = 22 Divide both sides by 22

x = 1

Substiture in 1 for x in either of the two original equations

2x +5y = 12

2(1) + 5y = 12

2 + 5y = 12 Subtract 2 from both sides

5y = 10 Divide both sides by 5

y = 2

(1,2)

2nd Problem

2x - 5y = 11 Multiply through by 2 4x - 10 y = 22

3x + 2y = 7 Multiply through by 5 15x + 10 y = 35

Add the two bold equation together

4x - 10y = 22

15x +10y = 35

19x = 57 Divide both sides by 19

x = 3

Substitute in 3 for x in one of the original equations to solve for y.

2x - 5y = 11

2(3) - 5y = 11

6 - 5y = 11 Subtract 6 from both sides

-5y = 5 Divide both sides by -5

y = -1

(3,-1)

User VRAwesome
by
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