Hello!
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10y + 7x = 29
-5y - 9x = 2
In this system, it would be easiest to eliminate y. Eliminate y by multiplying the bottom equation by 2:
10y + 7x = 29
2(-5y - 9x = 2)
Add the equations:
10y + 7x = 29
-10y - 18x = 4
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0y - 11x = 33
-11x = 33
-11x/(-11) = 33/(-11)
x = -3
Plug in the value of x into an equation to solve for y:
10y + 7(-3) = 29
10y - 21 = 29
10y = 50
y = 5.