Solve the system of equations by substitution.

x+y=20
y=4x

The solution of the system is
​(Simplify your answer. Type an ordered​ pair.)

The solution of the system is (4, 16)

y=-3x+27

2y-x+9=0

The solution is

  ​(Simplify your answer. Type integers or simplified fractions. Type an ordered​ pair.)

To solve this system of equations by substitution, we can substitute the expression for y from the first equation into the second equation:

2(-3x + 27) - x + 9 = 0

Simplifying this equation:

-6x + 54 - x + 9 = 0
-7x + 63 = 0
-7x = -63
x = 9

Now, we can substitute this value of x back into the first equation to find the value of y:

y = -3(9) + 27
y = -27 + 27
y = 0

Therefore, the solution to the system of equations is (9, 0).

4x+4y=-24

-3x+y=26

What is the solution of the ​system?
​(Type an ordered​ pair.)

To solve this system of equations by substitution, we can rearrange the second equation to solve for y:

-3x + y = 26
y = 3x + 26

Now we can substitute this expression for y into the first equation:

4x + 4(3x + 26) = -24
4x + 12x + 104 = -24
16x + 104 = -24
16x = -128
x = -8

Substituting this value of x back into the second equation:

-3(-8) + y = 26
24 + y = 26
y = 2

Therefore, the solution to the system of equations is (-8, 2).

3x-9y=1

9y=x-1
The solution is

First, rearranging the second equation to solve for x:

x = 9y + 1

Now, substitute this expression for x into the first equation:

3(9y + 1) - 9y = 1
27y + 3 - 9y = 1
18y + 3 = 1
18y = -2
y = -2/18
y = -1/9

Substituting this value of y back into the second equation:

9(-1/9) = x - 1
-1 = x - 1
x = 0

Therefore, the solution to the system of equations is (0, -1/9).