Solve using the elimination method

Question

Show your work.
x + 8y = 14
-3x + 4y = 0

Answer 1

1) Given that

x + 8y = 14-->1

-3x + 4y = 0-->2

Multiply equation (2) with 2

(-3x + 4y)2 = (0)-->2

-6x + 8y = 0 -->2

Substract equation 2 with 1

-6x + 8y - (x + 8y) = 0 -14

-6x + 8y - x - 8y = -14

-6x -x = -14

-7x = -14

x = 2

Substitute x = 2 in equation 2

-3(2)  + 4y = 0

-6 + 4y = 0

4y = 6

y = 6/4==>3/2

Therefore x = 2 and y = 3/2

 

Answer 2

eliminate variable x by multiplying the equation 1 by 3 and add the equation to 2.

3x + 24y = 42
-3x+4y = 0
----------------
28y = 42

divide each side by 28.

y = 42/28 = 1.5

substitute y = 1.5 in equation 1.

x + 8 * 1.5 = 14

x + 12 = 14

subtract 12 from each side .

x = 2

(x, y) = (2, 1.5).