How do you divide fractions?
1 answer:
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Answer:
The answer is a. 21.
Step-by-step explanation:
We solve this question by using Pythagoras theorem to relate the sides of a right angled triangle.
Here,
Hypotenuse of the given triangle(c)=75
Two sides of right angled triangle are:
a=72
b=?
Then,
for a given right angled triangle abc,
Using Pythagoras theorem,
Squaring on both sides,
or,
or,
or,
or,
∴
So, the value of b is obtained to 21 by the use of Pythagoras theorem.
The sum of the first n odd numbers is n squared! So, the short answer is that the sum of the first 70 odd numbers is 70 squared, i.e. 4900.
Allow me to prove the result: odd numbers come in the form 2n-1, because 2n is always even, and the number immediately before an even number is always odd.
So, if we sum the first N odd numbers, we have
The first sum is the sum of all integers from 1 to N, which is N(N+1)/2. We want twice this sum, so we have
The second sum is simply the sum of N ones:
So, the final result is
which ends the proof.