Subtract 5x from both sides of the equation:
y=9-5x
Substitute that for y in second equation:
10x-7(9-5x)= -18
Distribute:
10x-63+35x=-18
Combine like terms (x):
45x-63=-18
Add 63 to both sides:
45x=45
Divide by 45:
x=1
+37091 Multiply the FIRST equation by -2 to get
-10x -2y = -18 then add it to the SECOND equation
10x - 7y = -18
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-9y = -36 yields y = 4
Substitute this value of y into one of the equations to find 'x'
5x+y=9
5x +4 = 9
5x=5 x= 1
