-3+-6=-9 -9 is how many yards the football team has lost overall in the two plays
4 packs of bottled water (35*4=140)
7 packs of candy bars (20*7=140)
To solve for y, isolate the variable to one side.
9x+3y=4
-9x -9x
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3y= -9x+4
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3y= -9x+4 (Divide both sides by 3)
y=-3x+4