Question

Write a justification for each step
AB=BC
5y+6=2y+21
3y+6=21
3y=15
y=5
*I have to reason with it*

Answer 1

Do you know what substitution is

Answer 2

???????????????/

Answer 3

I edit the equation

Answer 4

for the problem:
5y+6=2y+21

since y=5 you do
5(5)+6=2(5)+21
25 +6=10+21

Answer 5

for the problem:
3y+6=21
do the same