Question

Solve and explain.

a+2a+9a = ​
​

Answer 1

12a

Explanation:

a + 2a + 9a

to simplify the expression, take out a common factor of a from each term

= a (1 + 2 + 9)

= a × 12

= 12a

Answer 2

Hello..! :)

`\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf \dashrightarrow \red{a+2a+9a }`

`\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf \dashrightarrow \blue{ \: 12a}`

To solve this simple problem, just add the numbers that are:

`\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf \dashrightarrow \green{9 + 2}`

But we must take into account that "a" in mathematics is an unknown and that it is only usually found in equations.

So, we must take a common factor from each term.

¿Doubts? On the comments. Greetings :D