David is twice as old as Abby. If a represents Abby’s age, which expression represents David's age? A) 3 + a
B) 2 + a
C) 2a
D) 3a

c 2a

Step-by-step explanation:

twice as old means your going to be multiplying

assuming you mean addition: addition and subtraction are reverse operations.

step-by-step explanation:

168

step-by-step explanation:

first off, we know that he drove 3.5 hours at a rate of 48 mph.

knowing that, we want to see how many miles he drove all-together.

in this case, we can just multiply 48 by 3.5.

48 * 3.5 = 168