Step 1) Because the second equation is already solved for yy we can substitute (5x - 7)(5x−7) for yy in the first equation and solve for xx:
3x - y = -63x−y=−6 becomes:
3x - (5x - 7) = -63x−(5x−7)=−6
3x - 5x + 7 = -63x−5x+7=−6
(3 - 5)x + 7 = -6(3−5)x+7=−6
-2x + 7 = -6−2x+7=−6
-2x + 7 - color(red)(7) = -6 - color(red)(7)−2x+7−7=−6−7
-2x + 0 = -13−2x+0=−13
-2x = -13−2x=−13
(-2x)/color(red)(-2) = (-13)/color(red)(-2)−2x−2=−13−2
(color(red)(cancel(color(black)(-2)))x)/cancel(color(red)(-2)) = 13/2
x = 13/2
Step 2) Substitute 13/2 for x in the second equation and calculate y:
y = 5x - 7 becomes:
y = (5 * 13/2) - 7
y = 65/2 - (2/2 xx 7)
y = 65/2 - 14/2
y = 51/2
The Solution Is: x = 13/2 and y = 51/2 or (13/2, 51/2)
