Th ratio of blue marbles to white marbles in a bag is 4 to 5.At this rate, how many blue marbles are there if there are 15 white marbles

There are 12 blue marbles.

Step-by-step explanation:

4/5 = x/15

Multiply both sides by 15.

60/5 = x

Simplify.

x = 12

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