Answer:
8)Answer x=3, y=-4
10)Answer x=2, y=2
Explanation:
8) y = -3x + 5 (1)
3x + 2 y = 1 2y=-3x+1 (2)
substitute (1) into (2) for y: 2[(-3x)+5]=-3x+1
-6x+10=-3x+1
-6x+3x=1-10
-3x=-9
x=-9/-3, x=3
plug x=3 into (1) y=-3(3)+5, y=-4
Answer (3,-4)
10) x + 3y = 8 x=-3y+8 (1)
3x + 3y = 12 3x= -3y+12 (2)
Substitute (1) into (2) for x: 3[(-3y)+8]=-3y+12
-9y+24=-3y+12
-9y+3y=12-24
-6y =-12
y=-12/-6
y=2
Plug y=2 in (1) x=-3y+8, x =-3(2)+8, x = 2
Answer (2,2)