I'm having trouble with simple arithmetic :
$$c_1+c_2=\frac{13}{10}$$
$$-2c_1+c_2=\frac{8}{10}$$

Question

I'm having trouble with simple arithmetic :
$$c_1+c_2=\frac{13}{10}$$
$$-2c_1+c_2=\frac{8}{10}$$

n00bstyle · Answer

Always think of substituting the one into the other.
First of all make sure to have as many unknows as you have eqations!

n00bstyle · Answer

In this case you have two unknows (c1 and c2), and two equations.
Calculate c1 from the first equation for example (c1 = 13/10 - c2).
Plug this into equation 2 and you can calculate c2.
After this, when c2 is known, you can plug it back into c1 = 13/10 - c2

hartnn · Answer

subtract the equations, whats the problem ??

anonymous · Answer

I know how to do substitution...my solution is different from chegg.com....that's why I want to see what other people are getting

hartnn · Answer

c1 =1/6 ??

anonymous · Answer

attachment

n00bstyle · Answer

and c2 is 17/15 I guess...

hartnn · Answer

the Q u asked and the pic have different equations...

anonymous · Answer

sorry

when I did the auxiliary equation, initially, I had c_1 and they called it c_2 and vice versa

hartnn · Answer

so, c1 = 1/6 and c2=17/15
for the Q u posted.

n00bstyle · Answer

You made a mistake:
add -1/2 - 3/10 = -5/10 - 3/10 = -8/10
In my opinion...

anonymous · Answer

I got 1/6 finally!!!!!!

anonymous · Answer

thanks guys, for a second I thought that the person posting on chegg.com made a mistake...turns out it was my mistake

n00bstyle · Answer

Well...it isn't rocketscience :D
Alright, good ;)