Answer:
a= 40-3b-c/5
a=-10+3b-2c
a=50+2b-3c/14
Explanation:
5a+3b+c-(3b+c)=40-(3b+c)
5a=40-3b-c
5a/5=40/5-3b/5-c/5
a= 40-3b-c/5
a-3b+2c-(3b+2c)=-10-(-3b+2c)
a=-10+3b-2c
14a-2b+3c-(-2b+3c)=50-(-2b+3c)
14a=50+2b-3c
14a/14=50/14+2b/14-3c/14
a=50+2b-3c/14