Econ-math question.
"lf we set the absolute value of the MRS(marginal rate of substitution) equal to the price ratio, we have the equation..."
So my mrs is -(y+1)/x+2 and my price ratio is simply one.
From there the instructor wrote (y+1)/(x+2) = 1, which makes sense because absolute value. He then has that = x-y=-1 and that's where I'm confused.

Question

Econ-math question. 
"lf we set the absolute value of the MRS(marginal rate of substitution) equal to the price ratio, we have the equation..."
So my mrs is -(y+1)/x+2 and my price ratio is simply one. 
From there the instructor wrote (y+1)/(x+2) = 1, which makes sense because absolute value. He then has that => x-y=-1 and that's where I'm confused.

phi · Answer

$$ \frac{(y+1)}{(x+2)} = 1 $$
multiply both sides by (x+2)
$$ \frac{(y+1)}{(x+2)}\cdot (x+2) = x+2 $$
and simplify

phi · Answer

y+1 = x+2

add -y to both sides
1 = x - y + 2
add -2 to both sides
-1 = x -y

anonymous · Answer

oy vey, i dont know why that was so hard for me to wrap my head around. thank you.

phi · Answer

You won't get tricked by that one anymore.

anonymous · Answer

Absolutely won't.