I had to do a recap of last years stuff and it's on linear equations and there are a whole bunch and I don't remember how to solve some of them... here is one that I don't know...I only remeber 2 ways to solve certain problems...what are the others?

1.)25x = 91 - 16y
16y = 64 - 16x

2.) 4x + 2y = 14
3x - y = 8

you've got 2 equations and 2 unknowns.
the first one you can rearrange.
16y=64-16x to 16x=64-16y
you can subtract 1 equation from the other
25x=91-16y
-16x=-64-(-16y)
______
9x=27 solve for x
then once x is known solve for y

your 2nd problem can be handled the same way
multiply both sides 3x-y=8 by 2
6x-2y=16.. Add the other equation
4x+2y=14
10x+0y=30 10x=30
or
divide the both sides of the first equation by 2
4x+2y=14 2x+y=7

add the 2nd equation again
2x+y=7
3x-y=8

5x=15. solve for x x=3

plug it back to 3(3)-y=8
9-8=y

hope this helps

Problem 1.

Equation 1 is 25x = 91 - 16y
Equation 2 is 16y = 64 - 16x
In Equation 2, we already have part of Equation 1, specifically a value for 16y. So we substitute that value into Equation 1.
25x = 91 -(64 - 16x)
25x = 27 + 16x
Subtract 16x from each side.
25x - 16x = 27 + 16x - 16x
9x = 27
Divide both sides by 9.
9x/9 = 27/9
x = 3

Now use that value of x in the first equation.
25x = 91 - 16y becomes
25(3) = 91 - 16y
75 = 91 - 16y
Subtract 75 from each side.
75 - 75 = 91 - 16y - 75
0 = 16 - 16y
Add 16y to each side.
0 + 16y = 16 - 16y + 16y
16y = 16
Divide both sides by 16.
16y/16 = 16/16
y = 1
The solution to Problem 1 is (3,1)

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Problem 2.
Equation 1 is 4x + 2y = 14
Equation 2 is 3x - y + 8

Using Eq. 1,
4x + 2y = 14 can be written as:
2(2x + y) = 14

Divide both sides by 2.
2x + y = 7

Subtract 2x from each side.
2x + y - 2x = 7 - 2x
y = 7 - 2x

Now use that value of y in Equation 2.
3x - y = 8
3x -1(7 - 2x) = 8
3x -7 + 2x = 8
5x - 7 = 8
Add 7 to each side.
5x -7 + 7 = 8 + 7
5x = 15
Divide both sides by 5.
x = 3
If x=3, then Equation 1 becomes:
4(3) + 2y = 14
12 + 2y = 14
Subtract 12 from each side.
12 = 2y - 12 = 14 - 12
2y = 2
y = 1

The solution to problem #2 is (3,1)