Question

I need help please.

Answer 1

You just need to translate the sentences into formulas: let x be the number, we have

• The difference of a number and 7 means $x-7$
• Twice that difference means $2(x-7)=2x-14$

So, the left hand side of our equation is 2x-14. Similarly, we have

• The sum of the number and 9 means $x+9$
• Three times that sum means $3(x+9)=3x+27$

So, the right hand side of our equation is 3x+27. We can set and solve the equation

$2x-14=3x+27 \iff -14-27=3x-2x \iff -41=x$

So, the solution is -41.