Homework help: use elimination to solve each system of equations?

Question

-5x + 3y= 6
x-y=4

If you would like your answer to be picked as the best answer, please do the following:

Please include all work

Please give steps on how you've completed it

Please give tips

Please give final answer in coordinates

Answer 1

x-y = 4
or, 5x - 5y = 20 (multiplying by 5)
or, 5x = 20+5y

from first equation , 5x = 3y-6
eliminating 5x,
3y-6=20+5y (=5x)
or,2y = -26
or, y = -13
hence, x - (-13)=4
or, x= -9

the solution set is (-9,-13)
I thought I have not understood the question properly,. however if it is the correct answer then there u r.

Tips:- here I've eliminated 5x, because it was easier, the places where u find eliminating multiples of x or y difficult, simply compare the values of a variable( x or y) derived from the 2 equation, the reduce it to a single one.

Answer 2

Multiply 2nd equation by 5 to eliminate x

-5x + 3y = 6
5x - 5y = 20

Add

-2y = 26

y = -13

Substitute to find x

x - y = 4 x + 13 = 4 x = -9 (-9, -13)

Answer 3

-5x + 3y = 6
x - y = 4

To use elimination, you need to be able to add or subtract the two equations together to get rid of one variable.

Let's get rid of y.

Multiply the second equation by 3 (because the first equation has 3y in it):

3x - 3y = 12

Now add that to the other equation:
-5x + 3y = 6
3x - 3y = 12
---------------
-2x + 0 = 18
-2x = 18
x = -9

Now put that back into one of the equations to find y:

x - y = 4
-9 - y = 4
-y = 13
y = -13

Solution is (-9, -13)

Answer 4

-5x + 3y = 6
x - y = 4-------------X by 5

-5x + 3y = 6
5x - 5y = 20----------Add

-2y = 26
y = -13

Now x - y = 4 so:-
x - (-13) = 4
x + 13 = 4
x = -9

Co- ordinates are (-9,-13)