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.
Answer:
5.63
Step-by-step explanation:
Angle NLM is equal to KLM - KLN.
Since KLM = 137° and KLN = 47°, NLM = °90. (Maybe it doesn't look like a right angle, but the math doesn't lie.)
Since NLM = 16y, then 90 = 16y.
Dividing both sides by 16, we find that:
y = 5.625
Answer:
ΔABC and ΔXYZ are SIMILAR by SSS property of similarity.
Step-by-step explanation:
SSS Similarity Theorem:
Two triangles are said to be similar if their CORRESPONDING SIDES are proportional.
In ΔABC and ΔXYZ, if , then △ABC∼△YZX
Here, in ΔABC and ΔXYZ
AB = 9, BC = x , AC = 12
Similarly, XY = 3, YZ = 2, ZX = 4
Here,
⇒ Corresponding sides are in the ratio of 3, if BC =6 units
Hence, if BC = 6 units, then the ΔABC and ΔXYZ are SIMILAR by SSS property of similarity.
Okay. So in order to solve this problem, we really have to try out each answer and divide it by 9. A is not correct, because it does not divide evenly. B works, but let's check the others. C and D do not work, but E also works as well. If you can have two answers, 504 and 882 are both exactly divisible by 9. The answers are B: 504 and E: 882.