14560=13000(1+r)^4/12
Now can you solve for r?
An exterior angle of a triangle is 180 degrees is never true. The simple reason behind this logic is that 180 degrees means a straight line and it is not possible for a straight line to create an exterior angle of a triangle. I hope that this answer will come to your help.
See below the theee of possibilities:
BBBB
BBBG
BBGB
BBGG
BGBB
BGBG
BGGB
BGGG
GBBB
GBBG
GBGB
GBGG
GGBB
GGBG
GGGB
GGGG
There are 16 differents possibilities.
In 11 of them have at least 2 boys
So probability is 11/16
Assuming you mean f(t) = g(t) × h(t), notice that
f(t) = g(t) × h(t) = cos(t) sin(t) = 1/2 sin(2t)
Then the difference quotient of f is

Recall the angle sum identity for sine:
sin(x + y) = sin(x) cos(y) + cos(x) sin(y)
Then we can write the difference quotient as

or

(As a bonus, notice that as h approaches 0, we have (cos(2h) - 1)/(2h) → 0 and sin(2h)/(2h) → 1, so we recover the derivative of f(t) as cos(2t).)
15a =6a - 90
Move all the numbers with variables to one side
15a - (6a) = 6a -(6a) -90
9a = -90
9a/9 = -90/9
a = -9
Hope this helps