The original price would have been $312.5
Answer : x= -4
This type of problem, you set them equal to each other. And then solve. Don’t forget you can multiply each side by denominator to eliminate the fraction.
Work:
we know that
In a parallelogram opposite angles are congruent and consecutive angles are supplementary.
So
m∠O=m∠M
m∠L=m∠N
m∠O+m∠L=
Step 
Find the value of x

Step 
Find the value of angle L
m∠L
m∠L
m∠L
Remember that
m∠N=m∠L
m∠N=
therefore
the answer is
the measure of the angle N is equal to 
in the like term you can add directly and make it single fraction and in unlike term you have to take LCM of denominator .
I’m pretty sure the slope is -1/2