How do you solve the following system: 10y=42+2x , 2x-4y=6 10y=42+2x,2x4y=6?

1 Answer
Jul 13, 2017

Put both equations in the same form and add or subtract to eliminate x then solve for y

Explanation:

Change the first equation to put x and y on the same side

10y - 2x = 42 + 2x -2x 10y2x=42+2x2x gives

10 y - 2x = 42 10y2x=42

Use the commuative property to change the second equation

2x - 4y = 6 : -4y + 2x = 62x4y=6:4y+2x=6

Now add the two equations

10y - 2x = 4210y2x=42
+-4y + 2x =6 ±4y+2x=6 This gives

6y = 48 6y=48 divide both sides by 6

6y/6 = 48/6 6y6=486 so

y = 6 y=6 Put 6 in for y and solve for x

10xx 6 = 42 + 2x10×6=42+2x

60 = 42 + 2x60=42+2x subtract 42 from both sides

60-42 = 42 -42 + 2x6042=4242+2x which gives

18 = 2x 18=2x divide each side by 2

18/2 = 2x/2 182=2x2 so

9 = x 9=x