C.4/11 is the answer
hope this helps ya ∩ω∩
D- 3.9, 3.6, 3.3
F- 25/35, 31/35, 36/35 or 1 and 1/35
the assumption being that the first machine is the one on the left-hand-side and the second is the one on the right-hand-side.
the input goes to the 1st machine and the output of that goes to the 2nd machine.
a)
if she uses and input of 6 on the 2nd one, the result will be 6² - 6 = 30, if we feed that to the 1st one the result will be √( 30 - 5) = √25 = 5, so, simply having the machines swap places will work to get a final output of 5.
b)
clearly we can never get an output of -5 from a square root, however we can from the quadratic one, the 2nd machine/equation.
let's check something, we need a -5 on the 2nd, so

so if we use a "1" as the output on the first machine, we should be able to find out what input we need, let's do that.

so if we use an input of 6 on the first machine, we should be able to get a -5 as final output from the 2nd machine.

Area of a circle = πr²
Area of a circle = 3.14 x 11² = 379.94 in²
Area painted in blue = 379.94 ÷ 2 = 189.97 in²
Area painted in purple = 189.97 in²
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Answer: 189.97 in²
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2.25*x=10
Which x is the number of books purchased
Solve for x
X=10÷2.25
X=4.44