Answer:
m<B = 141 degrees
Step-by-step explanation:
This shape is a heptagon meaning its angles should have a sum of 900 degrees.
we are given the degrees and we need to ad them up
148+90+120+129+130+142=749
then we subtract 749 from 900 which looks like
900-749=141
from subtracting 749 from 900 we get 141 hence we get our answer that m<B = 141 degrees
First, simplify out the brackets:
-20 - 4n = -12
Then, combine like terms by moving the -20 to the other side
-4n = -12 + 20
-4n = 8
Divide by -4 on both sides to isolate the n
n = 8/-4
n = -2