Question

Y=-2x+7and y=(b-5)x+7 and are parallel if b=

Answer 1

Y=-2x+7 has slope = -2
parallel lines have same slope so b must be equal 3 to have slope = -2
y=(b-5)x+7 = (3-5)x + 7 = -2x +7

answer
b = 3

hope it helps