Answer:
-3
Step-by-step explanation:
-7x=-2x+15
collect like terms
-7x+2x=15
-5x=15
divide both sides by -5
x=15/-5
x=-3
A) The coordinates of R is (-8,9)
B) The length of RS to the nearest tenth of a unit is 17.9
Let x the subject of the equation in x-2y=-10 this make it x=2y-10 substitute this in the first equation. 3(2y-10)-2y=-6 solve for y, y=6. substitute y in any of the original equations to get x x= 2

Thus, options A and D hold, from the simplifications above.
Let's consider the validity of the remaining options provided.




Hence, the correct options that apply are options A, D, E and F
Every difference of squares problem can be factored as follows: a2 – b2 = (a + b)(a – b) or (a – b)(a + b). So, all you need to do to factor these types of problems is to determine what numbers squares will produce the desired results. Step 3: Determine if the remaining factors can be factored any further.