For this case we have the following functions:

By definition of composition of functions we have:

Then substituting:

So:

Answer:

Answer:
y=2x+6 ; x+y=51
Step-by-step explanation:
assuming x is one number and y is the other -
one number (y) is 6 more (+6) than twice another (2x) -
using that knowledge we form an equation -
y=2x+6
the sum (x+y) is 51
using this knowledge we can make the equation -
x+y=51
now you have -
y=2x+6 or 2x-y=-6
x+y=51
using system of equations -
you add the equations -
3x=45
x=15
y=51-x => y=36
hope this helps!!
Answer:
9
Step-by-step explanation:
2x=28-10
2x=18
x=18÷2
x=9