solve using elimination method

[sisapeebles]

please help me solve using the elimination method:
0.3x - 0.2y=4
0.5x + 0.5y=85/19

thank you!!!

 

[Deleted member 4993]

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

 

[Denis]

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

Now follow Subhotosh's hints...