Question

PLSSS HELP ME OUT WITH THIS QUESTION, PLS PLS PLS AND PLS EXPLAIN!!!

Answer 1

Answer:

c 15

Step-by-step explanation:

-m-n=5

m+n=-5

(m+n)×(m-n)=m²-n²

m²-n²=-3×-5=15

Answer 2

Answer:

C. 15

Step-by-step explanation:

1. First, let's solve the system of equations; $-m - n = 5, m - n = -3$

Solve -m - n = 5 for m.

• $-m -n = 5$
• $-m-n+n=5+n$
• $-m = n + 5$
• $\frac{-m}{-1} = \frac{n+5}{-1}$
• $m = -n - 5$

Substitute -n - 5 for m in m - n = -3.

• $m - n = -3$
• $-n - 5 - n = -3$
• $-2n-5=-3$
• $-2n-5+5=-3+5$
• $-2n = 2$
• $\frac{-2n}{-2} = \frac{2}{-2}$
• $n = -1$  

Substitute -1 for n in m = -n - 5.

• $m = -n - 5$
• $m = -(-1) - 5$
• $m = 1 - 5$
• $m = -4$

2. Okay, now that we know m = -4 and n = -1, let's solve for m^2 -n^2.

• $m^2-n^2$
• $(-4)^2-(-1)^2$
• $16 - (-1)^2$
• $16 - 1$
• $15$

Therefore, the answer is C. 15!