Question about Algebra!!!?

-5x+3y=6

x-y=4

x-y=4

x = 4+y

substitute in eq1

-5x+3y=6

-5(4+y) +3y = 6

-20 -5y +3y =6

-2y = 6+20

y = 26/-2

y = - 13

substiture the value of y in equation 1

-5x+3y=6

-5x +3(-13) = 6

-5x - 39 = 6

x = (6 +39)/-5

x = 45 /-5

x = -9

answer is (-9, -13)

chk by substituting the values of x and y in equations..

-5x+3y=6

-5(-9) +3(-13) = 6

+45 - 39 = 6

6=6

I'm not going to do your homework for you, but as a math tutor, I would ask this question, which one is a simpler substitution. Hopefully you would respond solving for "x" in the second equation. I prefer to deal with positive numbers whenever possible!

Step 1 - perform the same operation to each side of the second equation by adding "y" to both sides.

(Your equation now looks like this: x=4+y)

Step 2 - substitute the above equation for "x" in the first equation. Don't forget the parenthesis!

-5(4+y)+3y=6

Step 3 - solve for y.

Step 4 - plug and chug. Put in your "y" result in either equation and solve for "x".

Step 5 - Check your work!

find y in the second equation and substitute into first:

y = x - 4

-5x + 3(x-4) = 6

-2x - 12 = 6

2x = -18

x = -9

put x into one of the equations and solve:

-9 - y = 4

y = -13

-5x+3y=6

x-y=4

x= -9,

y = -13

from eq 2 you get x=4+y

substitute that into eq 1 and solve for y, then use y to determine x