How do you solve the following system: 8x-3y=3, x+3y=3 ?

2 Answers
May 13, 2018

This ordered pair is (2/3, 7/9) or (0.bar6, 0.bar7).

Explanation:

Use the elimination method, and then substitution to solve. Line up the two equations, one on top of the other:

8x - 3y = 3
color(white)(8)x + 3y = 3

Now add them together, and notice that y will be eliminated because -3y + 3y = 0:

8x color(blue)(- 3y) = 3
color(white)(8)x color(blue)(+ 3y) = 3


color(white)(x)9x color(white)(+ 0y) = 6

9x = 6

x = 6/9 rarr 2/3

Now substitute that value for x into another equation, and solve for y:

x + 3y = 3

2/3 + 3y = 3

2 + 3(3)y = 3(3)

2 + 9y = 9

9y = 7

y = 7/9

So this ordered pair is (2/3, 7/9). As a repeating decimal, the coordinates are (0.bar6, 0.bar7).

May 13, 2018

Solution: x= 2/3 and y= 7/9

Explanation:

8 x-3 y=3 ; (1) , x +3 y =3; (2) , adding equation (1)

and equation (2) we get, 9 x = 6 :. x = 6/9 or x= 2/3

Putting x=2/3 in equation (2) we get, 2/3 +3 y =3; or

3 y =3- 2/3 or 3 y = 7/3 or y = 7/9

Solution: x= 2/3 and y= 7/9 [Ans]