Answer:
The answer to your question is A.35
A^2 - b^2 = (a - b)( a +b);
<span>cos^4x-sin^4x =( cos^2x + sin^2x )( cos^2x - sin^2x) = 1* cos2x = co2x.</span>
(x+4)(x+4+1) = (x+1)(x+1+11)
(x+4)(x+5) = (x+1)(x+12)
x^2 + 4x+5x+20=x^2+x+12x+12
9x + 20 = 13x + 12
13x-9x = 20-12
4x = 8
x = 2

Substitute
, so that
, and

which is separable as

Integrate both sides with respect to
. For the integral on the left, first split into partial fractions:



Solve for
:






Replace
and solve for
:


Now use the given initial condition to solve for
:

so that the particular solution is

Answer:
So first you have to do 12-2 since it's in parenthesis. It is 10. 5+4 is 9, and 9 times 10 is 90. 3 squared is 9, then you divide 90 by 9. The answer is 10.