Question

Which expression equals 6 when a = 5 and b = 1/3?

Answer 1

Answer: a+3b=6

Explanation:

I thunked about it

Answer 2

A)
`9b^2 + 3a - 10`

Explanation:

The given choices are

A) 9b^2 + 3a - 10

B) a^2 - 20 - 3b

C) 3(a - 2) - a + a 6b

D) 9b + ab

Now, we need to evaluate each expression and see which one gives 6 as result.

We know that
`a=5` and
`b=(1)/(3)`

A)

`9b^2 + 3a - 10=9((1)/(3) )^(2)+3(5)-10=9 * (1)/(9)+15-10=1+5=6`

Choice A is part of the right answer, because is equal to 6.

B)

`a^2 - 20 - 3b=(5)^(2)-20-3((1)/(3) )=25-20-1=5-1=4`

Choice B is not part of the right answer.

C)

`3(a - 2) - a + a 6b=3(5-2)-5+5(6)((1)/(3))=3(3)-5+10=9+5=14`

Choice C is not part of the answer.

D)

`9b + ab=9((1)/(3))+5((1)/(3) )=3+(5)/(3)=(9+5)/(3)=(14)/(3)`

Therefore, the only expression which is equal to 6 when a = 5 and b = 1/3 is choice A.