3r = 10 + 5s, when r = 10
3r = 10 + 5s, where r = 10Substitute 10 for r.3(10) = 10 + 5s30 = 10 + 5sSubtract 10 from each side.20 = 5sDivide by 5.4 = s
3(10)=10+5s30=10+5s20=5s4=s