Question

What is the value of the unknown number in the verbal description? 5 times the sum of 12 and a number is 80.

Answer 1

Answer: D. 4

Step-by-step explanation:

Let the unknown number be x.

The given verbal description :  5 times the sum of 12 and a number is 80.

i.e. $5(12+x)=80$

To solve the above equation, first divide 5 on both sides of the equation, we get

$12+x=16$

Now, Subtract 12 on the both sides of the equation, we get

$x=16-12=4$

Hence, the unknown number is 4.

Answer 2

"5 times a sum of 12 and a number is 80" translates to the next equasion:

5 x (12+a) = 80

Now we just have to solve it to find the value of a.
$5 \times (12 + a) = 80 \\ 60 \times 5a = 80 \\ 5a = 80 - 60 \\ 5a = 20 \\ a = 20 \div 5 \\ a = 4$
The unknown number is 4.
D is the right answer.