I think you have to follow someone and ask them to be your tutor.
You're original equation has a -81, so the factored form will have to have a positive and negative multiplying one another to achieve that...
f(x) = x(x + 9)(x - 9)
Its impossible to draw a trapezoid with just three right angles.
a trapezoid has 4 sides, which means all the angles inside the trapezoid must add up to 360 degrees.
if you have just 3 right angles (90x3), you already use up 270 degrees. Leaving you with just 90 degrees left, which is also a right angle. That means, there has to be four, if you have at least 3.
Answer: 31 nickels and 29 dimes
<u>Step-by-step explanation:</u>
Nickels (.05): x
Dimes (.10): y
Value: .05x + .10y = 4.45 → -20(.05x + .10y = 4.45) → -x - 2y = -89
Quantity: x + y = 60 → 1(x + y = 60) → <u> x + y </u> = <u> 60 </u>
-y = -29
y = 29
Next, substitute "29" for "y" into either equation and solve for "x":
x + y = 60
x + 29 = 60
x = 31