Help with simultaneous equation?

Multiply the first coefficient of the bottom equation by the top equation. Multiply the first coefficient of the bottom equation by the top equation. Subtract the two equations from each other.

10x + 20y = 35

-(10x - 4y = 32)

24y = 3

y = 1/8

Substitute y into 10x - 4y = 32

10x = 32.5

x = 32.5/10=3.25

x = 13/4

Substitute both values into each of the original equations to prove my answer.

Multiply the second equation by 2: 10x - 4y = 32

Add the 2 equation together

(2x+10x)+(4y-4y) = 7+32

12x = 39

x = 39/12

x= 13/4

make Y the subject of the left side and then substitute them both into 1 equation

2x+4y = 7 (make this Equation1)

5x - 2y = 16 (make this equation 2)

change E1 so that Y is the subject

4y = 7 - 2x

y = 7 - 2x OVER 4 (E3)

change E2 so that Y is the subject =

-2y = 16 - 5x

2y = -16 + 5x

y = -16 + 5x OVER 2 (E4)

then sub E3 into E4

change it to:

10x + 20y = 35 (everything x5) and

10x - 4y = 32

Since both 10x's are positive (+) we subtract everything else. (Same, sign, subtract)

10x - 10x = Nothing

20y - -4y = 24y

35 - 32 = 3

So 24y = 3 so y = 0.125

Now we put it in the equation, 2x + 4y = 7

2x + 4 x 0.125 = 7

2x + 0.5 = 7

2x = 7 - 0.5

2x = 6.5

x = 3.25

So, x = 3.25 and y = 0.125

Hope that helped, it's definitly not easy :P