Question 280032
-7x-8y=9 multiply by 9
-4x+9y=-22 multiply by 8 & add.
-63x-72y=81
-32x+72y=-176
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-95x=-95
x=-95/-95
x=1 ans.
-7*1-8y=9
-7-8y=9
-8y=9+7
-8y=16
y=16/-8
y=-2 ans.
SOLUTION: (1,-2)
-7x-8y=9
-8y=7x+9
y=7x/-8+9/-8 
y=-7x/8-9/8 (red line)
-4x+9y=-22
9y=4x-22
y=4x/9-22/9 (green line)
{{{ graph( 300, 200, -6, 5, -10, 10, -7x/8 -9/8 , 4x/9 -22/9 ) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions -7x/8 -9/8 and 4x/9 -22/9).