Respuesta :

"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.
[tex]5 \times (12 + a) = 80 \\ 60 \times 5a = 80 \\ 5a = 80 - 60 \\ 5a = 20 \\ a = 20 \div 5 \\ a = 4[/tex]
The unknown number is 4.
D is the right answer.

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. [tex]5(12+x)=80[/tex]

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

[tex]12+x=16[/tex]

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

[tex]x=16-12=4[/tex]

Hence, the unknown number is 4.