Make sure you make me brainest
Answer:
1.-6
Step-by-step explanation:
I don't know how to do the second one but
BD = DC
x+8 = 3x+2
2x=-4
x=-2
-6+12
-6
This is an arithmetic series, so we know, that:
Sum = (First term + Last term) * Number of terms /2
Here we have:
First term = 33
Last term = 104
Number of terms = 104 - 33 + 1 = 72
and