sisapeebles said:

please help me solve using the elimination method:

0.3x - 0.2y=4

0.5x + 0.5y=85/19

thank you!!!

Suppose the equations are:

ax + by = c and......................(1)

dx + ey = f ...........................(2)..........................(where a,b,c,d,e &f are non-zero constants)

Then we multiply top equation by 'd' and bottom equation by 'a'. We get

adx + bdy = cd..............................(3)

adx + aey = af..............................(4)

Now subtract (4) from (3) - We get

y (bd-ae) = cd - af (where bd-ae is not equal to zero)

y = (cd - af)/(bd -ae)

You found the value of 'y'.

Use this value in (1) or (2) to find 'x'.

Finally check your answer, by putting these values of 'x' and 'y' in (1) and (2).

If you need more refresher, go to:

http://www.purplemath.com/modules/systlin6.htm