The ratio of red marbles to blue marbles in a bag is 3 to 4 which of the following is possible total number of marblesa. 21b.30c. 32d. 40

Option A.

Step-by-step explanation:

Given : ratio of red marbles to blue marbles in a bag is equal to 3 to 4 .

We need to find which of the options: A, B, C and D is true .

Here, 3 + 4 = 7

Therefore, sum of number of red marbles and number of blue marbles should be multiple of 7 ,hence the answer has to be a multiple of 7.

Now, option B is 30 which is not multiple of 7 .

Option C is 32 which is not multiple of 7 .

Option D is 40 which is not multiple of 7.

Option A is 21 which is a multiple of 7 .

Therefore, the only multiple of 7 on the list is A. 21

So, total number of marbles can be 21 .

Therefore the answer is A

step-by-step explanation:

first, eliminate the parenthesis:

3

x

+

2

−

4

x

second, group like terms:

3

x

−

4

x

+

2

third, combine like terms:

(

3

−

4

)

x

+

2

→

−

1

x

+

2

→

−

x

+

2