# solve using elimination method

#### sisapeebles

##### New member
0.3x - 0.2y=4
0.5x + 0.5y=85/19

thank you!!!

#### Subhotosh Khan

##### Super Moderator
Staff member
sisapeebles said:
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

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

#### Denis

##### Senior Member
sisapeebles said:
0.3x - 0.2y=4
0.5x + 0.5y=85/19
Start by multiplying by 10 to get rid of decimals:
3x - 2y = 40
5x + 5y = 850/19