Question

Solve the proportion.
10/a = 15/30


A. 2

B. 20

C. 5

D. 10

Answer 1

(10)/(a)=(15)/(30)

Since there is one rational expression on each side of the equation, this can be solved as a ratio. For example, (A)/(B)=(C)/(D) is equivalent to A*D=B*C.
10*30=15*a

Since a is on the right-hand side of the equation, switch the sides so it is on the left-hand side of the equation.
15*a=10*30

Multiply 15 by a to get 15a.
15a=10*30

Multiply 10 by 30 to get 300.
15a=300

Divide each term in the equation by 15.
(15a)/(15)=(300)/(15)

Simplify the left-hand side of the equation by canceling the common factors.
a=(300)/(15)

Simplify the right-hand side of the equation by simplifying each term.
a=20

Answer 2

so,
its letter B. 20

Answer 3

thnxs bro :)

Answer 4

your welcome :)

Answer 5

too long.