How do I solve for elimination method on this problem: 0.3x - 0.2y=4 and 0.3x + 0.3y= 5/19. I know that multiply by 10 on both equations and get 3x-2y=40 and 3x+3y=50/19. and then I have to multiply 3x-3y=40 by 3 and 3x+3y= 50/19 by -3 to get 9x-9y=120 and -9x-9y=-150/19. But from there I get lost. Can someone please help me?
2 answers
I just did your earlier problem. Please study that. If you can do one you can do them all.
first if you have .3 x in both, why multiply by 10?
.3 x - .2 y = 4
.3 x + .3 y = 5/19
subtract second from first
0 x - .5 y = 71/19
y = - 142/19
so
.3 x - .2 (-142/19) = 40
3 x = -2(142/19) + 760/19
3 x = 476/19
x = 476/57
.3 x - .2 y = 4
.3 x + .3 y = 5/19
subtract second from first
0 x - .5 y = 71/19
y = - 142/19
so
.3 x - .2 (-142/19) = 40
3 x = -2(142/19) + 760/19
3 x = 476/19
x = 476/57
1 answer