Question

A certain number was multiplied by 4. Then, this product was divided by 19.4. Finally 6.4 was subtracted from this quotient, resulting in a difference of -8.4, What was this number?

Answer 1

-9.7

Explanation:

we can do the opposite of everything that was done to get the resulting difference

so......

-8.4+6.4=-2

-2x19.4=-38.8

-38.8/4=-9.7

and to double check.......

-9.7x4=-38.8

-38.8/19.4=-2

-2-6.4=-8.4