Respuesta :
The easiest way to do this is to plug everything in the left side and see what equals 10, but you could also solve for c (which I will show you).
2c+5(c-5)=10
2c+5c-25=10
7c-25=10
7c=35
c=5
2c+5(c-5)=10
2c+5c-25=10
7c-25=10
7c=35
c=5