20x+ 5y = 15
Move 20x to the other side. Sign changes from +20x to -20x
20x-20x+5y=-20x+15
5y=-20x+15
Divide both sides by 5
5y/5=y ( Cross out 5 and 5, divide by 5, 1*1*y=y)
-20/5=-4x
15/5=3
y=-4x+3 or y=3-4x
Answer: y=-4x+3 or y=3-4x
Answer:
14 trees is less than 640 inches
Answer:
Train A = 128
Train B = 68
Step-by-step explanation:
We can set up a system of equations for this problem
Let A = # of tons of Train A
Let B = # of tons of Train B
A + B = 196
A = B + 60
Now, we plug in A for the first equation, using substitution
(B+60) + B = 196
2B + 60 = 196
Subtract 60 from both sides
2B = 136
Divide both sides by 2
B = 68
Plug in 68 for B in the 2nd equation
A = 68 + 60
A = 128
Checking work: 128 + 68 = 196 :D hope this helped
C ) price Decrease and quantity decrease
Let the first and smaller number be x. Since the second number is 5 times the first, the second number is 5x. We also know both of these numbers must add to 50; thus, we can create the following equation.

Combine like terms

Divide both sides by 6

This is the value of the first number. The number you're looking for isn't specified in the question description, so I'll just provide the value of the second number. The second number has to be 5 times the first.
Thus, we just multiply 5 to x.

That's the value of the second number.