{3x+y=11 , 2x+4y = 8?

Question

USE SUBSTITUTION TO SOLVE EACH SYSTEM OF EQUATIONS. CHECK SOULTION?
SUMMER HELP PLEASE

Answer 1

The easiest to solve for is the y in the first equation

y=-3x+11

The substitute that after the 4 in the second

2x+4(-3x+11) = 8
2x - 12x +44 =8
-10x = -36
x= 3.6

y=0.2

Answer 2

1) 3x + y = 11

2) 2x + 4y = 8

First, divide both sides of equation 2 by 2

2a) x + 2y = 4

You can either solve equation 1 for y and substitute the result into equation 2a, or solve equation 2a for x and substitute the result into equation 1

1) 3x + y = 11
y = 11 - 3x

2a) x + 2y = 4
x + 2(11 - 3x) = 4
x + 22 - 6x = 4
-5x = - 18
x = 18/5

Substitute into equation 1

3(18/5) + y = 11
3(18) + 5y = 55
54 + 5y = 55
5y = 1
y = 1/5

Check

2x + 4y = 8
2(18/5) + 4(1/5) = 8
36/5 + 4/5 = 8
40/5 = 8
8 = 8

Answer 3

Divide the 2nd equation by 2 on left and right

(2x +4y)/2 = 8/2
x+2y = 4

Subtract 2y from both sides

x +2y -2y = 4 - 2y
x= 4-2y

Since we know that x=4-2y, we can plug that into the first equation

3x+y = 11
3(4-2y) +y = 11
12 - 6y +y = 11
-5y = -1
y = 1/5

x = 4-2y
x = 4 -2(1/5)
x = 20/5 -2/5
x = 18/5

Check the answers
3x+y = 11
3(18/5) + 1/5 = 11
54/5 +1/5 = 11
55/5 = 11
11=11

The first equation checks out. Now, substitute your answers for the second
2x +4y = 8
2(18/5) + 4(1/5) = 8
36/5 + 4/5 = 8
40/5= 40/5
The second equation checks out. Thus, the answer is

x= 18/5
y = 1/5

Answer 4

y = 11 - 3x

2x + 4.(11 - 3x) = 8
2x + 44 - 12x = 8
- 10x = - 36
x = 36/10 = 18/5

y = 11 - 54/5
y = 55/5 - 54/5
y = 1/5

x = 18/5 , y = 1/5

Answer 5

solve the top equation for y, substitute the "x" expression into the second equation to find x. Once you find x, substitute it back into any of the eqautions to find y. To check, plug the values of x and y into BOTH equations to make it balances.

Answer 6

y = 11 - 3X
2X + 4(11 - 3X) = 8
2X + 44 - 12 X = 8
36 = 10 X: X = 3.6
Y = 11- 3*3.6 = .02

My answer checks, You should check it too.