Question

plz help me understand this

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


3.) x+y=0 4.) 3x - 4y = -5
x=y+4 x = y+2

Answer 1

What are we supposed to do
I see a bunch of equations running together ....

1.) 6x - 3y = 6 ---> y = 2x - 2

etc ?

Answer 2

I think I see systems of equations:

1.) 6x - 3y = 6
y= 2x + 5

2.) y= -2/3x +4
2x + 3y = -6

3.) x+y=0
x=y+4

4.) 3x - 4y = -5
x = y+2

All you need to do here is set up things in a standard way and solve the pairs of equations. I'll do #2 and you can try the others.
#2.
y= -2/3x +4
2x + 3y = -6

2/3 x + y = 4
2x + 3y = -6

2x + 3y = 12
2x + 3y = -6

Hmm. no solution here
Let's try #1:

6x - 3y = 6
y= 2x + 5

6x - 3y = 6
-2x + y = 5
multiply the 2nd by 3 and add:
6x - 3y = 6
-6x + 3y = 15
WAK! Again no solution.

#3.
x+y=0
x=y+4

x + y = 0
x - y = 4
add 'em
2x = 4
x = 2
y = -2

#4.
3x - 4y = -5
x = y+2

3x - 4y = -5
x - y = 2
multiply the 2nd by 3 and subtract the 1st:
3x - 4y = -5
3x - 3y = 6

y = 11
x = 13

If I read the problems wrong, write them right and you take a stab at solving them.