Question

The sun of six times a number and 7 more than the number is the same as the difference between -20 and twice the number. What is the number?

Answer 1

The sum of six times a number and 7 more than the number can be represented as 6x + (x+7)

Is the same as the difference between -20 and twice the number, which can be represented as -20 - 2x

Now, the equation would be :

`6x\text{ +(x+7)=-20-2x}`

We need to solve for x:

`6x\text{ +x+7=-20-2x}`
`7x+7=-20-2x`

Add both sides 2x

`7x+7+2x=-20-2x+2x`
`9x+7=-20`

Subtract both sides by 7:

`9x+7-7=-20-7`
`9x=-27`

Divide both sides by 9:

`(9x)/(9)=(-27)/(9)`
`x=-3`