(IF YOU ANSWER THE QUESTIONS) It's a little time consuming but I want to see who can answer the fastest. I would really appreciate the answers to these asap. ONLY ANSWER IF YOU KNOW HOW TO DO THESE!!! They're easy but I don't want to do them.
Appreciate = Will mark Brainliest if correct
Thanks so much

1) x=−4, y=−20

2) x=−1, y=3

3) x = 7 , y=4

4) x = -6.5 , y = -10.5

Step-by-step explanation:

1) y=5x;−3x+2y=−28

solving system by substitution:

substitute y =5x into 2nd equation:

-3x +2*5x =-28 → -3x+10x = -28 → 7x = -28 → x = -4

plug in  x in any equation and solve for  y = 5* -4 = -20

2) solving system by elimination:

Multiply the first equation by 7, and  the second equation by 5.

7(4x−5y=−19)

5(3x+7y=18)

28x−35y=−133

15x+ 35y= 90

Add them up to eliminate y:

43x=−43 divide both sides by 43

x=−1

plug x back into 1st equation to solve for y

4x−5y=−19

(4)(−1)−5y=−19

−5y−4=−19 add 4 to both sides

−5y=−15 divide by -5

y=3

3) y =4 , 5x -6y = 11

plug in 4 for y in 2nd equation and solve for x:

5x -6* 4 =11 simplify

5x - 24 = 11 add  24 on each side

5x = 11 +24 simplify

5x = 35 divide by 5 on each side

x =7

4) y = x -4, 2x - y = -2.5

use substitution method:

2x -(x-4) = -2.5 distribute ( )

2x-x+4 = -2.5 simplify

x + 4 = -2.5 subtract 4 on each side

x = -2.5 -4

x = -6.5

plug in -6.5 for x in 1st equation and solve for y:

y = -6.5 -4

y = -10.5

step-by-step explanation:

i am not sure sorry : c