y = (3-x)/2

y = 2x-16

2x-16 = (3-x)/2

4x – 32 = 3-x

5x =35

x = 35/5 = 7

y = 2(7)-16

y = 14-16 = -2

x+2y=3 and 2x-y=16

in order to isolate the x of one equation i am going to move the rest of the equation onto one side of the equal sign.

x+2y-2y=3-2y so it would look like this x=3-2y

you can put this value for x in the other equation so it will read:

2(3-2y)-y=16 (distribute the 2)

6-4y-y=16 (subtract 6 and move it other and add your variables)

-5y=10 (divide by -5)

y=-2

then you substitute -2 for y and get:

x+ 2(-2)=3 (multiply and add)

x= 7

2. dx+ey=f

3. eax+eby=ec from (1)

4. bdx+bey=bf from (2)

5. (ea-bd)x = ec-bf from (3,4)

6. x = (ec-bf)/(ea-bd) from (5)

above gives the idea

1. x+2y = 3

2. 2x-y = 16

3. 4x-2y = 32

(multiplying (2) by 2)

4. 5x = 35

(adding (1) and (3))

5. x = 7

(dividing (4) by 7)

6. 7 +2y = 3

(substituting 7 for x in (1))

7. 2y = -4

(simplifying (6))

8. y = -2

(simplifying (7)

answer x = 7, y = -2

2x-y=16

You want the second equation to have -2y. Multiply the second equation by 2. you get 4x-2y=32. Add the 2 equations.the 2y cancels out.3x=19, x=19/3. Plug in.

-y = 16 – 2x

y = 2x – 16

x + 2(2x-16) = 3

x + 4x – 32 = 3

5x = 35

x = 7

7 + 2y = 3

2y = -4

y = -2

Check:

x = 7

y = -2

7 – 4 = 3

14 + 2 = 16