3X+y=2

7x-4y=30
Solve the system of equations

7 answers

To solve this system of equations, we can use either the substitution method or the elimination method.

Here, we will use the elimination method to solve the system of equations:

1. Multiply the first equation by 4 and the second equation by 3 to make the coefficient of y the same in both equations:

4(3x + y = 2) becomes 12x + 4y = 8
3(7x - 4y = 30) becomes 21x - 12y = 90

2. Add the two equations together to eliminate y:

12x + 4y + 21x - 12y = 8 + 90
33x - 8y = 98

3. Solve for x:

33x - 8y = 98
33x - (8)(3x) = 98
33x - 24x = 98
9x = 98
x = 98 / 9
x = 10.888

4. Substitute the value of x back into one of the original equations to solve for y. We will use the first equation:

3x + y = 2
3(10.888) + y = 2
32.664 + y = 2
y = 2 - 32.664
y = -30.664

Therefore, the solution to the system of equations is x = 10.888 and y = -30.664.
No decimals
To solve the system of equations without decimals, we can use the elimination method:

1. Multiply the first equation by 4 and the second equation by 3 to make the coefficient of y the same in both equations:

4(3x + y = 2) becomes 12x + 4y = 8
3(7x - 4y = 30) becomes 21x - 12y = 90

2. Add the two equations together to eliminate y:

12x + 4y + 21x - 12y = 8 + 90
33x - 8y = 98

3. Solve for x:

33x - 8y = 98
33x - 8(3x) = 98
33x - 24x = 98
9x = 98
x = 98 / 9
x = 10

4. Substitute the value of x back into one of the original equations to solve for y. We will use the first equation:

3x + y = 2
3(10) + y = 2
30 + y = 2
y = 2 - 30
y = -28

Therefore, the solution to the system of equations is x = 10 and y = -28.
It’s wrong.. write it like this (__,__)
Let's solve the system again using the elimination method:

1. The given equations are:
3x + y = 2 ...(1)
7x - 4y = 30 ...(2)

2. Multiply equation (1) by 4 and equation (2) by 1 to eliminate y:
12x + 4y = 8 ...(3)
7x - 4y = 30 ...(4)

3. Add equations (3) and (4) to eliminate y:
19x = 38
x = 38 / 19
x = 2

4. Substitute the value of x back into equation (1) to find y:
3(2) + y = 2
6 + y = 2
y = 2 - 6
y = -4

Therefore, the solution to the system of equations is (2, -4).
Solve the system of equations
2x+6y=-18
x=5y-1
To solve the system of equations, we can substitute the expression for x from the second equation into the first equation and solve for y.

Given equations:
1. 2x + 6y = -18
2. x = 5y - 1

Substitute x from equation 2 into equation 1:
2(5y - 1) + 6y = -18
10y - 2 + 6y = -18
16y - 2 = -18
16y = -16
y = -1

Now, substitute y back into equation 2 to find x:
x = 5(-1) - 1
x = -5 - 1
x = -6

Therefore, the solution to the system of equations is x = -6 and y = -1.