Obviously, what you looking for is slopes. Now let's get started. 6.) 7x-5y=20 You subtract 7x both sides. -7x -7x -5y=-7x+20 Then you divide -5 both sides (which is include -7 and 20). y=7/5x-4 Simplify. -8x-3y=12 Add 8x both sides because it's a negative number. +8x +8x -3y=8x+12 Divide -3 both sides. y=-8/3x-4 Simplify. And your point value is (0,-4). 7.) -x-4y=12 Add x both sides. +x +x -4y=x+12 Divide -4 both sides. y=-1/4x-3 Simplify. 20x+80y=0 Subtract 20x both sides. -20x -20x 80y=-20x Divide 80 both sides. Here's a hint: 20/80 is same thing as 2/8, so you don't have to do all that. y=1/4x Simplify. Here's another hint: I bet you wondering there's no y- intercept. The y-intercept is (0,0). Both of the functions are parallel, so there's no solution. 8.) 30x+50y-100=0 Add 100 both sides. +100 +100 30x+50y=100 Subtract 30x both sides. -30x -30x 50y=-30x+100 Divide 50 both sides. y=-3/5x+2 Simplify. 3x-15y-30=0 Add 30 both sides. +30 +30 3x-15y=30 Subtract 3x both sides. -3x -3x -15y=-3x+30 Divide -15 both sides. y=1/5x-2 Simplify. And your point value is (5,-1). I hope it helps.
