5x - y = -4 x+3y=-4 also 4x-5y=2 6x-3y=12?

Question

solve both and show work please

Answer 1

First equation set:

A) 5x - y = -4
B) x + 3y = -4

We can use A to solve for Y: --> y = 5x + 4
and then plug this into B
x + 3(5x + 4) = -4
x + 15x + 12 = -4
16x = -16
x = -1

plug this X into B to solve for Y
x + 3y = -4
-1 + 4 = -3y
3 = -3y
y = -1


2nd equation set:

A) 4x - 5y = 2
B) 6x - 3y = 12

Divide all of B by 3 to simplify: --> 2x - y = 4
Then, solve for Y: --> y = 2x - 4

Plug this Y into the A equation to solve for X:
4x - 5(2x - 4) = 2
4x - 10x + 20 = 2
-6x = -18
x = 3

Given x = 3, we can plug this into our solve Y of y = 2x - 4
y = 2(3) - 4
y = 2

Answer 2

First:
5x - y = -4
Solve for y:
-y = -4 - 5x
Multiply each piece by -1
(-y * -1) = (-4 * -1) - (5x * -1)
and you get:
y = 4 - (-5x)
or
y = 4 + 5x

Next:
-4x + 3y = -4
Since we are trying to solve for y:
3y = -4 + (-4x)
or
3y = -4 - 4x

Now substitute the first equation into the "y" of the second equation:
3(4 + 5x) = -4 - 4x
Simplify the left side:
12 + 15x = -4 - 4x
Put all the "x" information on the left:
12 + 15x + 4x = -4
Put all the non-"x" information on the right:
15x + 4x = -4 - 15
Simplify:
19x = -19
Solve for x:
x = -19/19
x = -1


As a side note:
You could also have made the second equation = just "y" by doing the following:
y = (-4 - 4x)/3
But, you should see that makes it a little more difficult.


So that should give you enough help for you (or someone else) to solve the second one. :)

Answer 3

9

Answer 4

lol, show work? That would take a while to just type it out. I'll just tell you how to do it. If you have a graphing calculator, type the values into the matrix, and it will give you x and y. OR if you want to do it by hand, just substitute. Slove for one variable, and then plug that into the other equation, and you will get the answer to one variable. Then just slove for the variable that is left!

Answer 5

y=3x-8 it incredibly is hassle-free because of the fact the addition/subtraction technique -(y=4-x) ------------------Bieber did the substitution technique 0=4x-12 x=3 x+y=0 -(3x+y=-8) ---------------- -2x=8 x=-4

Answer 6

I wish I knew.