Question

Right and solve an equation to find the number n.four times a difference of a number and seven is 12

Answer 1

For this case we must propose an algebraic expression associated with:

"four times a difference of a number and seven is 12"

So we have to:

Four times a difference of a number and seven is represented as: $4 (n-7)$

So we have the expression is:

$4 (n-7) = 12$

We apply distributive property to the terms within parentheses:

$4n-28 = 12$

We add 28 to both sides:

$4n = 12 + 28\\4n = 40$

We divide between 4 on both sides:

$n = \frac {40} {4}\\n = 10$

Answer:

$n=10$