Answer:
1. 7
2. 48
Step-by-step explanation:
you have to <u>subtract</u> 49-42 because some got taken away then you should end up with 7, 63-15 is 48.
Here's a pattern to consider:
1+100=101
2+99=101
3+98=101
4+97=101
5+96=101
.....
This question relates to the discovery of Gauss, a mathematician. He found out that if you split 100 from 1-50 and 51-100, you could add them from each end to get a sum of 101. As there are 50 sets of addition, then the total is 50×101=5050
So, the sum of the first 100 positive integers is 5050.
Quick note
We can use a formula to find out the sum of an arithmetic series:

Where s is the sum of the series and n is the number of terms in the series. It works for the above problem.
The bisector of the angle at A (call it AQ) divides the segment BC into segments BQ:QC having the ratio AB:AC. Use this fact to find x.
.. 9:15 = (2x -1):3x
.. 15(2x -1) = 9*3x . . . . . the product of the means equals the product of extremes
.. 30x -15 = 27x
.. 3x = 15
.. x = 5
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According to the value of x, the bisector AQ divides the triangle into two isosceles triangles: ABQ, ACQ.
Answer:
20 units
Step-by-step explanation:
The 3 part of the ratio refers to 15 units
Divide 15 by 3 to find the value of one part of the ratio
15 ÷ 3 = 5 ← value of 1 part of the ratio, thus
4 parts = 4 × 5 = 20 units ← perimeter of larger figure