Answer is 10 because I just took the test
= cos( -x ) * [ - sin( - x ) ] = cosx * sinx ;
cosx * sin x is the right answer !
A. $40, because you would do 1,000 × 1.04 = $1,040, and then subtract the original $1,000.
b. $81.60, because 1,000 × 1.04² = 1,081.6
c. $480.24, because 1,000 × 1.04^10 = 1,480.24.
I have used the formula for compound interest presuming you were aware of it, but I will be happy to explain what I did if you want :).
I hope this helps!
Let x represent the length of the shorter leg.
Longer leg: 5x +19
Hypotenuse: 5x +20
Pythagorean theorem:
.. x^2 +(5x +19)^2 = (5x +20)^2
.. x^2 +25x^2 +190x +19^2 = 25x^2 +200x +20^2 . . . . . . eliminate parentheses
.. x^2 -10x -39 = 0
.. (x -13)(x +3) = 0
.. x = 13 . . . . . . . . . . leg lengths must be positive
The side length of the triangle are 13, 84, 85 feet.