Answer:
answer is 7y+20
Step-by-step explanation:
We take x as the value that is missing the equation of BC is 7y+x
Total =13y+25
8y+5+7y+x=13y+25
8y+7y+5+x=13y+25
13y+5+x=13y+25
13y-13y+x=25-5
X=20
