Since you have y alone on one side of the equation......
Use substitution and plug in 1/2x-4 for y in the other equation.

Distribute

Combine like terms

Add 8 to both sides

Divide by 4
and 
Plug this value in for x

Simplify

Multiply everything by 8 and simplify

Divide.....

Your answers are:

Answer:
Step-by-step explanation:
1 sandwich is 6.25 (because 31.25/5)
2 sandwiches is 12.5
3 sandwiches are 18.75
4 sandwiches are 25
5 sandwiches are 31.25
6 sandwiches are 37.5
Amy - 8s + 12
8(6.25) +12 = 62
Amy paid $62.
Bob - 8(s + 2)
8(6.25 + 2) = 66
Bob pays $66.
Cathy - 4(2s + 3)
4(2 x 6.25 + 3) = 62
Cathy paid $62.
(4^8)w This is the answer
Answer:
f(x) = x + 4
Step-by-step explanation:
Given
y - x - 4 = 0 ( add x to both sides )
y - 4 = x ( add 4 to both sides )
y = x + 4 ( let y = f(x) )
f(x) = x + 4
Answer:
it is a polynomial
3a^2+a^2= 4a^2
4a^2+6
Step-by-step explanation:
3a^2 +a^2 = 4a^2+6
=4a^2+6