What should be the first step in adding these equations to eliminate y
8x+3y= 2
+ 4x-by=-7

Step-by-step explanation:

Are you sure you wanted that "b" in the second equation?

If so, here's how we eliminate y:

1) Multiply the first equation by b:  8bx + 3by = 2b

2) Multiply the second equation by 3:  12x - 3by = -21

3) Combine these two results.  We get:

(8b + 12)x = 2b - 21

Here we have eliminated  y, but still have an equation in two variables, b and x.

answer: (c) m∠qpo + (2x + 16)° = 180°

step-by-step explanation:

the opposite angles of a quadrilateral are supplementary.

so, ∠o + ∠q = 180°   and   ∠p + ∠r = 180°

since ∠r = 2x + 16°, we can use substitution as follows:

∠p + ∠r = 180°

∠p + (2x + 16)° = 180°