Question

What is the value of s in the equation 3r = 10 + 5s, when r = 10?

Answer 1

The value of s is 4.

First, substitute 10 for r into the equation.

3r=10+5s

3(10)=10+5s

30=10+5s

Now the equation can be solved as normal. Subtract 10 from both sides of the equation to isolate s.

30-10=10-10+5s

20=5s

Divide 5 on both sides.

$\frac{20}{5}$=$\frac{5s}{5}$

4=s

Answer 2

3(10) = 10 + 5s
Multiply 3 and 10 together
30 = 10 + 5s
subtract 10 from both sides to cancel it out on right side
20= 5s
divide by 5 to both sides
4 = s