For the substitution method do you put the variable in front?
ex: 4r+s=19
-4r -4r
s=?

Question

For the substitution method do you put the variable in front?
ex: 4r+s=19
    -4r     -4r
           s=?

the_fizicx99 · Answer

What do you mean substitution method, you're subtracting 4r from both sides, why?

anonymous · Answer

I have to use the substitiution method to answer this question: $$5r+2s=23      $$
$$4r+s=19$$

anonymous · Answer

$$4r+s=19$$
$$4r=19-s$$
$$4r-19=-s$$
$$\frac{ 4r-19 }{ -1 }=\frac{ -s }{ -1 }$$
$$s=-4r+19$$

Plug in for s in first equation.

$$5r+(-4r+19)=23$$
$$5r+-4r+19=23$$
$$r+19=23$$

Subtract 19 from 23

$$r=4$$