SOLUTION: The sum of a number and 9 is multiplied by -2 and the answer is -8. Write and solve an equation to find the number.

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: The sum of a number and 9 is multiplied by -2 and the answer is -8. Write and solve an equation to find the number.      Log On


   

Question 1170180: The sum of a number and 9 is multiplied by -2 and the answer is -8. Write and solve an equation to find the number.
Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!


x is "the number"


"The sum of a number and 9" is +red%28x+%2B+9%29+


"...multiplied by -2" +red%28-2%28x%2B9%29%29+


"...equals -8" +red%28-2%28x%2B9%29+=+-8%29+


To solve this means to isolate x on one side (then the other side is 'the number').
Divide both sides by -2:
+x%2B9+=+4+

Subtract 9 from both sides:
++highlight%28+x+=+-5+%29+

Check: -2(-5+9) = -2(4) = -8 (ok)