Which of the following are like terms in this expression? 12a-7+7a+12b. A. 7 and 7a. B. 12 and 12a. C. -7and 12b. D. 7a and 12a.

D. 7a and 12a

Step-by-step explanation:

7a and 12a both have the variable a, raised to the first power

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.

(f+g)(x) = 3^x+10x+4x-2

      =3^x +14x-2

choice b