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:

$\frac{9x}{9}=\frac{-27}{9}$$x=-3$