9 or -9 ...if I’m wrong sorry
Let sister be s. Matthew, M
Matthew is 7years older than twice the age of his sister
M = 7 + 2s
13 = 7 + 2s. 7 crosses the equality to other side and becomes -7
13 - 7 = 2s
6 = 2s Divide both sides by 2
6/2 = 2s/2
3 = s
Sister is 3 years old.
1. AB 3-2/-1-1
-1/2
BC 2+1/1+3
3/4
AC 3+1/-1+3
4/2=2
It is a right triangle
2. JK -1-2/4+3
-3/7
LM -2+5/-5-2
-3/7
KL -1+5/4-2
<u>4/2=2</u>
JM 2+2/-3+5
<u>4/2=2
</u><u />The quadrilateral is a parallelogram
The answer i D because 11-6=5
