I'll explain it simply for you
1st question
Of course you know phythagoras theorm
You even wrote it up there
It states that the sum of the square of the two sides of an equilateral triangle is equal to the square of the hypotenuse

Where C is the hypotenuse
*NOTE* :
HYPOTENUSE is the greatest side in a triangle!!
And that's where your mistake is!
So you should take the greatest side as C
So in Q3. 7, 24 and 26 are the given numbers
You'll make the smaller two numbers a and b and the greatest number C
Using the Formula you'll solve the left side first which is

Then the right side which is

And if both are equal then it is a right triangle otherwise it isn't!
Let
a=7
b=24
c=26
a^2 + b^2
7^2 + 24^2
49 + 576 = 625
GREAT, Now the right side
26^2 = 676
Since they aren't equal it isn't a right angled triangle...
Then let
a=7.5
b=10
c=12.5
7.5^2 + 10^2
= 56.25 + 100
= 156.25
12.5^2 = 156.25
They are EQUAL
Therefore it is a right triangle too
Hopefully I helped
Answer: 
Step-by-step explanation:
Given : In a sociology class there are 14 sociology majors and 11 non-sociology majors.
Total students = 14+11=25
Number of students are randomly selected = 3
Then, the number of ways to select 3 students from 25 students :-

Number of ways to select at least 2 of the 3 students re non-sociology majors :-

The probability that at least 2 of the 3 students selected are non-sociology majors will be :-

Answer:
c
Step-by-step explanation:
#2) 435+25x=875-15x
40x=440
x=11
the answer is 11 weeks.
#3) 2500(3x) for x=10
2500(3*10)
2500(30)
7500
the answer is 7500 bacteria after 10 months.
Answer:
$33
Step-by-step explanation:
because iring gigapos