Algebra Equation

Question

X+2y=4

3x-4y=7

solve

Answer 1

Multiplying the first equation by 2 we obtain 2x+4y=8 and 3x-4y=7. Adding the two equations together we have 5x=15 so that x=3. Plugging it into the first equation we have 3+2y=4 or 2y=1 or y=1/2.

Answer 2

x + 2y = 4

3x - 4y = 7

Step 1:

2( x + 2y = 4)

3x - 4y = 7

We now distribute the 2 and we get: 2x + 4y = 8

3x - 4y = 7

Step 2:

We add the equations together and we get:

2x + 3x = 5x

8 + 7 = 15

5x = 15

x = 3

Step 3:

We now plug our x-value into either equation to find our y-value.

3x - 4y = 7

3( 3) -4y = 7

9 - 4y = 7

-4y = -2

y = 1/2

Our solutions are x = 3 and y = 1/2