
Step-by-step explanation:
So we go backwards, since we have x= 1/2 , 7

Now we have to foil to get the quadratic

We must simplify the terms

Our final result comes out to be

The old photocopier can make x manuals in an hour. The new photocopier can make 4x. Combined, they made 5x manuals in an hour.
In one hour they can make 1/28 of the manuals.
1/(28*5)=1/140 is the rate.
The new photocopier can make all the manuals in 4/140 or 35 hours.
The old one can make them in 140 hours.
The language art teacher wants to know the opinion of the ENTIRE school, so it would be fair if the teacher takes a sample from the ENTIRE school population. She can use the stratified sampling method where she can take a proportionate sample from each grade.
Correct answer: All students in each grade
Points that are given on x+y=4 are (0,4),(3,1) and (4,0) and points that are give for x-y=2 are (0,-2),(2,0) and (3,1)