Y = mx + b, m = 0. The equation becomes y = b, where b is the y-coordinate of the y-intercept.
I believe it's A. Day 1 decreased by half from 8 would be 4. Day 2 decreased by half from 4 would be 2. Day 3 decreased by half from 2 would be 1. then .5 would be decrease by. 25, which would be .75. I hope that makes sense:)
Simple way to see it is to multiply the value opposite of the axis you're flipping it over by -1. For example the point (-5,7) would become (5,7) when reflected over the y-axis, because the point is moving from the left to the right. This means the triangle would be (1,3) (5,3) and (5,7) when reflected over the y-axis. For reflection over the x-axis it would be (-1,-3) (-5,-3) and (-5,-7) because each point is moving down.
The answer is (5x - 4y)(2a + b)
10ax + 5bx - 8ay - 4by = 10ax + 5bx - (8ay + 4by) =<span>
= 5x * 2a + 5x * b - (2a * 4y + b * 4y) =
= 5x(2a + b) - 4y(2a + b) =
= (5x - 4y)(2a + b)</span>
