Question

2a+5c=6
4a-5b=-7
-6c= -12

Answer 1

c= 12/6
c= 2

2a+5.2=6
2a=6-10
a= -4/2
a= -2

4.(-2) - 5b= -7
-5b= -7+(-8)
5b= 15
b= 3