Answer:
11. x = 6; y = 6.5
12. x = 2; y = 4
Step-by-step explanation:
In each figure, the hash marks on the lines indicate the parallel lines (marked with red arrows) are equally-spaced. That means the two expressions involving x are equal to each other, and the two expressions involving y are equal to each other.
__
11. 2x +1 = x +7
x = 6 . . . . . . . subtract (x+1) from both sides
and
3y -8 = y +5
2y = 13 . . . . add (8-y) to both sides
y = 6.5 . . . . divide by the coefficient of y
__
12. x +3 = 3/2x +2
1 = 1/2x . . . . . subtract (x+2)
2 = x . . . . . . . multiply by 2
and
2y -1 = 3y -5
4 = y . . . . . . add (5 -2y)
