Some math equations.?

Question

2x - 4y = 18
-3x + 2y = -19

9x + 12y =45
-3x + 2y = 21

-24x + 40y = -32
3x + 4y = 13

Answer 1

1)2x-4y=18
-3x+2y=-19

Multiply the second equation by 2:
2x-4y=18
-6x+4y=-38
=========
-4x=-20
x=5

2(5)-4y=18
10-4y=18
-4y=8
y=-2

The solution set is (5,-2)

Check:
2(5)-4(-2)=18
10+8=18
18=18

-3(5)+2(-2)=-19
-15-4=-19
-19=-19

2)Multiply the second equation by -6:
9x+12y=45
18x-12y=-126
==========
27x=-81
x=-3

9(-3)+12y=45
-27+12y=45
12y=72
y=6

The solution set is (-3,6)

Check:
9(-3)+12(6)=45
-27+72=45
45=45

-3(-3)+2(6)=21
9+12=21
21=21

3)Multiply the second equation by -10:
-24x+40y=-32
-30x-40y=-130
===========
-54x=-162
x=3

-24(3)+40y=-32
-72+40y=-32
40y=40
y=1

The solution set is (3,1)

Check:
-24(3)+40(1)=-32
-72+40=-32
-32=-32

3(3)+4(1)=13
9+4=13
13=13

I hope this helps and good luck with your math class!

Answer 2

try setting one equation equal to just 1 variable and plugging it into your 2nd. i.e.:

2x-4y=18
4y=2x-18
y=.5x-4.5

-3x+2(.5x-4.5)= -19
-3x+x-9= -19
-2x=-10
x=5

then substitute it into the original equation to solve for y

2(5)-4y=18
10-4y=18
-4y=8
y= -2


hope this helps, give it a try on the other 2

Answer 3

Is this ur math homework u are such a cheater! Thats no way to help your mind get any smarter! At least try the mand talk to your teacher before cheating!