Answer:
D) Isosceles
Step-by-step explanation:
An isosceles triangle is the triangle that has 2 sides that are the same.
First ask yourselfhat needs to be dristributed.
That would be -1 (x-9)
To distribute you have to multiply the number out side of the parentheses (-1) by each term inside the parentheses( x and -9)
-1×x=-x
-1×-9=9
Now the expression is
-x+9+4x
To simplify you have to combine like terms (4x and-x)
4x-x=3x
Your answer is 9+3x or 3(3+x).
Answer:
The best prediction for the population in year 25 is 
Step-by-step explanation:
we have a exponential function of the form
where
a is the initial value
b is the base
In this problem
so
For 
substitute
Round up
Answer:
D sentence 5
Step-by-step explanation:
Answer:
x=nπ3, n∈I
Step-by-step explanation:
sin x + sin 5x = sin 2x + sin 4x
⇒⇒ 2 sin 3x cos 2x = 2 sin 3x cos x
⇒⇒ 2 sin 3x(cos 2x - cos x) = 0
⇒ sin 3x=0 ⇒ 3x=nπ ⇒ x=nπ3⇒ sin 3x=0 ⇒ 3x=nπ ⇒ x=nπ3 , n∈I, n∈I
or cos 2x−cos x=0 ⇒ cos 2x=cos xcos 2x-cos x=0 ⇒ cos 2x=cos x
⇒ 2x=2nπ±x ⇒ x=2nπ, 2nπ3⇒ 2x=2nπ±x ⇒ x=2nπ, 2nπ3 , n∈I, n∈I
But solutions obtained by x=2nπx=2nπ , n∈I, n∈I or x=2nπ3x=2nπ3 , n∈I, n∈I are all involved in x=nπ3x=nπ3 , n∈I
