<h2>
Answer:</h2>
We will use substitution to solve this system for x.

Now that we know what x is, we can determine y by pluging in -3 for x in one of the original equations. I will use the first one.

We now have our solution.
D. 
We can check our answer by pluging the solution into one of the original equations to see if both sides equal each other. I will use the first equation.

Since the equation checks out, our solution is correct.
B. False questions worth 3 ...
Answer:
A. 3x^2+7x^2+2×3x ×7-84x = 3x^2+7x^2-2×3x×7
9x^2+49x^2+42x-84 x= 9x^2+49x^2-42x
9x^2+49x^2-42 = 9x^2+49 x^2-42x
verified
B.
U should add all the #s together so... it = 11.3
then divide by the # of terms. so...... 11.3/ 14= 0.9357 (rounded makes 0.94)
So .... B
19 - 1 = 18 and 7 - 6 = 1
Since anything multiplied by 1 is itself, the answer is 18.