Answer:
a = -5
Step-by-step explanation:
15 - a = 20
Move the constant of 15 to the other side by subtracting it.
-a = 5
Divide by -1 to make a positive.
Check.
15 - (-5) = 20
15 + 5 = 20
20 = 20
(i think) they are congruent
The tick marks show that they are congruent by SSS
the mean of 2,5,8,9,7/6,3,5,1,4, is 4.2
and the mean of 2,5,8,9,76,3,5,1,4, is 5
hope this helps have an amazing day and be safe
