Question

Solve by the multiplication with add or subtract method
5x + 2y = -8
3x + 7y = 1

Answer 1

5x + 2y = -8 ---->(-3)
3x + 7y = 1----->(5)
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-15x - 6y = 24 (result of multiplying by -3)
15x + 35y = 5 (result of multiplying by 5)
----------------add
29y = 29
y = 29/29
y = 1
now sub 1 in for y in either equation to find x
5x + 2y = -8
5x + 2(1) = -8
5x + 2 = -8
5x = -8 - 2
5x = -10
x = -10/5
x = -2
check..
3x + 7y = 1
3(-2) + 7(1) = 1
-6 + 7 = 1
1 = 1 (correct)

x = -2 and y = 1 or (-2,1)

Answer 2

Can you help me with
3x - 4y = 45
7x + 6y = 13

Answer 3

3x - 4y = 45 --->(3)
7x + 6y = 13 --->(2)
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9x - 12y = 135 (result of multiplying by 3)
14x + 12y = 26 (result of multiplying by 2)
------------------add
23x = 161
x = 161/23
x = 7
now sub 7 in for x in either equation to find y
3x - 4y = 45
3(7) - 4y = 45
21 - 4y = 45
-4y = 45 - 21
-4y = 24
y = 24/-4
y = - 6
check...
7x + 6y = 13
7(7) + 6(-6) = 13
49 - 36 = 13
13 = 13 (correct)

x = 7 and y = -6 or (7,-6)