Question

@halorazer
Solve by the linear combination method (with or without multiplication).

x + y = 40
0.08x + 0.03y = 1.7


A.
(40, 60)

B.

(20, 20)


C.
(10, 30)

D.
(20, –50)

Answer 1

-12.5(.08x+.03y=1.7)
-x-.375y=-21.25
Now we can combine this with x+y=40

x+y=40
-x-.375y=-21.25
0x+.625y=18.75
.625y=18.75
/.625
y=30
Now just put that back into .08x+.03y=1.7
.08x+.9=1.7
-.9
.08x=.8
/.08
x=10

(10,30)
So, C.

Answer 2

THANK YOU SO MUCH! I've been trying to figure out how to do that for like an hour o.0 Thank you! :D

Answer 3

You're very welcome. :) If you need anymore help, you know where to find me.

Answer 4

Yep :D