Solve this system of equations using substitutions?

Question

6.2x-0.5y= -27.8
0.3x+0.4y=68.7

*please show steps
Thanksss!! best answer will be rewarded!

Answer 1

6.2x - 0.5y= -27.8 -- A
0.3x+0.4y=68.7 --B

To solve for x
Multiply eq.A with 0.4
Multiply eq.B with 0.5 and you have

2.48x-0.2y =-11.12
0.15x +0.2y =34.35

Solving the equations simultaneously you have
2.63x=23.23
x=23.23/2.63
x=8.86

To find y
substitute for x in A

54.93 - 0.5y =-27.8

-0.5y = -27.8-54.93
-0.5y=-82.73 (the minus cancels out)
y=83.73/.5
y=165.46

Answer 2

6.2x - 0.5y = -27.8
6.2x = 0.5y - 27.8
x = (0.5y - 27.8)/6.2

0.3x + 0.4y = 68.7
0.3((0.5y-27.8)/6.2) + 0.4y = 68.7
0.3(0.5y - 27.8) + 2.48y = 425.94
0.15y - 8.34 + 2.48y = 425.94
2.63y = 434.28
y = 434.28/2.63

x = (0.5y - 27.8)/6.2
x = (0.5*(434.28/2.63) - 27.8)/6.2
6.2x = (0.5*(434.28/2.63) - 27.8
6.2x = 217.14/2.63 - 27.8
6.2x = (217.14 - 73.114)/2.63 = 144.026/2.63
x = 144.026/16.306

(Don't know if you need to convert those to whole numbers or not, but that is simple enough if you need to do so.)

Answer 3

6.2x-0.5y=-27.8
6.2x = 0.5y-27.8
Divide by 6.2
x = 0.5/6.2 y - 27.8/6.2 --(1)

0.3x+0.4y = 68.7
Substitute x
0.3(0.5/6.2 y - 27.8/6.2)+0.4y=68.7
0.424y = 70
y = 165

Substitute into (1)
x = 0.5/6.2 (165) - 27.8/6.2
x=8.82