@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)

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)

anonymous · Answer

-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.

anonymous · Answer

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

anonymous · Answer

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

anonymous · Answer

Yep :D