Answer:
x=5 feet
Step-by-step explanation:
At floor level y=0
If the expression is:

But, with the negative sign, the answer is x= 5i (where i is imaginary)
Given, arc QR is congruent to arc LN and arc OP is congruent to arc VW.
And the expressions for each arc in the diagram also given as:
Arc QR = 2x - y, arc LN = 11 , arc OP= 10 and arc VW=5x+y.
Hence, we will get the system of equations as following:
Arc QR = Arc LN
2x - y = 11 ...(1)
Arc OP = Arc VW
5x + y = 10 ...(2)
We need to find the value of x. So, we can add the equations to eliminate y so that we can solve the equations for x. Therefore,
2x+5x = 11 + 10
7x = 21
Divide each sides by 7.
So, x= 3
180 is the degree of the whole angle so you subtract 180 from 77 to get P
180-77=103
P=103
She began with 20.
If she bought 7 more books and ended up with 17, that means she had ten beforehand. If she had half remaining, we simply double it, thus getting 20.