show how to solve these problems:

1. 6x - y = -4
2x + 2y = 15 answer:x = 1/2
y = 7

2. x +y = 1 x = -1/3
2x - y = -2 y = 4/3

3. x - y = 3 x = 5/2
6x + 4y = 13 y = - 1/2

I just need to know how to solve these problems. Please show me how it is done.

Do them all the same way: either by combining equations in a way that cancels out one unknown, or by substitution.

Here is how problem #3 can be solved:
Substitute y + 3 for x in the second equation,
6(y+3)+ 4y = 13
10y + 18 = 13
10 y = -5
y = -1/2
x = y+3 = 5/2

Now you try the others.

To solve these problems, you can use the method of substitution or elimination. I will demonstrate the process using the method of substitution for each problem:

1. Problem:
6x - y = -4 (Equation 1)
2x + 2y = 15 (Equation 2)

Step 1: Solve Equation 1 for one variable (in terms of the other variable).
6x - y = -4
y = 6x + 4 (Equation 3)

Step 2: Substitute Equation 3 into Equation 2.
2x + 2(6x + 4) = 15
2x + 12x + 8 = 15
14x + 8 = 15

Step 3: Solve for x.
14x = 15 - 8
14x = 7
x = 7/14
x = 1/2

Step 4: Substitute the value of x back into Equation 3 to find y.
y = 6(1/2) + 4
y = 3 + 4
y = 7

Therefore, the solution is x = 1/2 and y = 7.

2. Problem:
x + y = 1 (Equation 1)
2x - y = -2 (Equation 2)

Step 1: Solve Equation 1 for one variable.
x + y = 1
x = 1 - y (Equation 3)

Step 2: Substitute Equation 3 into Equation 2.
2(1 - y) - y = -2
2 - 2y - y = -2
2 - 3y = -2

Step 3: Solve for y.
2 - 3y = -2
-3y = -2 - 2
-3y = -4
y = -4/(-3)
y = 4/3

Step 4: Substitute the value of y back into Equation 3 to find x.
x = 1 - (4/3)
x = 3/3 - 4/3
x = -1/3

Therefore, the solution is x = -1/3 and y = 4/3.

3. Problem:
x - y = 3 (Equation 1)
6x + 4y = 13 (Equation 2)

Step 1: Solve Equation 1 for one variable.
x - y = 3
x = y + 3 (Equation 3)

Step 2: Substitute Equation 3 into Equation 2.
6(y + 3) + 4y = 13
6y + 18 + 4y = 13
10y + 18 = 13

Step 3: Solve for y.
10y + 18 = 13
10y = 13 - 18
10y = -5
y = -5/10
y = -1/2

Step 4: Substitute the value of y back into Equation 3 to find x.
x = (-1/2) + 3
x = -1/2 + 6/2
x = 5/2

Therefore, the solution is x = 5/2 and y = -1/2.

I hope this helps! Let me know if you have any further questions.