Question

The system of equations y=-3x+5 and y=3x-7 has

Answer 1

y = -3x + 5
y = 3x - 7

-3x + 5 = 3x - 7
+ 3x + 3x
5 = 6x - 7
+ 7 + 7
12 = 6x
6 6
2 = x

y = -3x + 5
y = -3(2) + 5
y = -6 + 5
y = -1
(x, y) = (2, -1)

Answer 2

`\displaystyle \left \{ {{y=-3x+5} \atop {y=3x-7}} \right. \Rightarrow \left \{ {{y+3x=5} \atop {y-3x=-7}} \right. \\ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~2y/=-2 \Rightarrow y=- (2)/(2) \Rightarrow y=-1 \\ y+3x=5 \\ -1+3x=5 \\ 3x=5+1 \\ 2x=6 \\ x= (6)/(2) \\ x=3`