Answer:
The mean is 20
Step-by-step explanation:
17+19+21+23=80
80 div 4 = 20
if you meant x^2+9x+20 then it is (x+4)(x+5) you know that because 4+5=9 and 4x5=20 using FOIL
It's 67/100 because a percent is out of 100 which is already simplified
3 yrs ago:
Alice - x
Jane - 3x
Fast forward 2 years... 1 year ago:
Sum of their ages = 62
Equation to solve: x + 3x = 62
4x = 62
----- -----
4 4
x = 15.5
From this, we can deterime that Alice is 15 1/2 years old.
Then, plug in 15.5 for x in 3x to find Jane's age.
15.5 × 3 = 46.5
From this, we can determine that Jane is 46 1/2 years old.
I hope this helps you to understand this problem better.
Answer:

Step-by-step explanation:
Notice that all three sides of the given triangle has one tick mark.
This means that all three sides are congruent, meaning that we have an equilateral triangle.
And for equilateral triangles, all three angles are also congruent.
So:

Also, recall that the interior angles of a triangle is always 180. Thus:

Substitute:

Combine like terms:

Substitute:

Multiply:

Thus:

And we are done!