DE/2 = 30.5
CE=30.5
DC=30.5
3x + 5 = 30.5
3x = 30.5 - 5
3x = 25.5
25.5/3 =8.5
x=8.5
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:
Step-by-step explanation:
Given the inequality
, we need to solve for "x".
We can subtract
to both sides:

(This step is shown in the exercise)
Now, we can add 10 to both sides:
(This step is not shown in the exercise)
And finally, divide both sides by -3:

(This is shown in the exercise)
Therefore, the missing step is:
Remember: 50% means 1/2. So, if 18 is 50%, or 1/2, of a number, the number must be double 18.
18 x 2 = 36
18 is 50% of 36.