Solve for the variable in the following proportion.

4 is to 5 as 10 is to a

8
12
12.5
20

(c) The value of variable a  is 12.5.

Step-by-step explanation:

4 is to 5 as 10 is to a.

or, 4 : 5 = 10 : a

By the RATIO OF PROPORTIONALITY:

or, the value of a  = 12. 5

⇒ 4 is to 5 as 10 is to 12.5

Hence, the value of variable a  is 12.5.

12.5

Step-by-step explanation:

4/5=10/x

cross product

5*10=4*x

50=4x

x=50/4

simplify,

x=25/2

x=12.5

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!

can i see the following ?

step-by-step explanation: