solve: c+s+r=13.5
6c+3s+r=42
r=2s

Question

solve: c+s+r=13.5
           6c+3s+r=42
            r=2s

shayaan_mustafa · Answer

Hi krystilmrotte :)

How are you?

anonymous · Answer

good how are you

shayaan_mustafa · Answer

So you have to find the values of c, s and r.

shayaan_mustafa · Answer

Me too fine dear.

anonymous · Answer

yup and im tottsaly confused on how to find them

shayaan_mustafa · Answer

First eliminate r from both upper two equations.

shayaan_mustafa · Answer

Put r=2s in,
c+s+r=13.5
c+s+2s=13.5
c+3s=13.5

Put r=2s in
6c+3s+r=42
6c+3s+2s=42
6c+5s=42

Uptil now you have cleared?

anonymous · Answer

still confused....

shayaan_mustafa · Answer

Where ? What step you did not get?

anonymous · Answer

after the second "put r+2s"

shayaan_mustafa · Answer

I didn't written put r+2s anywhere.

Look our first objective is to reduce the all three equations into the two equations.

So therefore, when we say two equation then we mean that there must be two variables.

Like in the question you have given with 3 equation so there must be 3 variables too. As we have namely, c, s and r.

shayaan_mustafa · Answer

Do you know this all?