Question

3x+5=20 solve for x and show work

Answer 1

`\boxed {\tt x=5}`

Explanation:

We want to solve for
`x`, therefore we must isolate it on one side of the equation. The equation is:

`3x+5=20`

5 is being added to 3x. The inverse of addition is subtraction. Subtract 5 from both sides of the equation.

`3x+5-5=20-5`

`3x=20-5`

`3x=15`

x is being multiplied by 3. The inverse of multiplication is division. Divide both sides of the equation by 3.

`(3x)/(3)=(15)/(3)`

`x=(15)/(3)`

`x=5`

Let's check our solution. Plug 5 in for x and solve.

`3x+5=20`

`3(5)+5=20`

`15+5=20`

`20=20`

This checks out, so we know our solution is correct.

The solution to 3x+5=20 is x=5.