Answer:
3/20
Step-by-step explanation:
1/4 - 1/10
= 10/40 - 4/40
= 6/40
= 3/20
Answer:
1. Since the angles on the both sides are the same
5x = 100
x = 20
The mistake is that it is absolutely unnecessary to use 180.
2. It is a right angle, which means it would be 90 degrees instead of 180.
3x + 39 = 90
3x + 39 - 39 = 90 - 39
3x = 51
3x = 17
3. The process is wrong
It should be
6x + 2x + 8 = 180
8x + 8 = 180
8x = 172
x = 21.5
Answer:
190 chairs
Step-by-step explanation:
-This is an arithmetic progression with the first term a=10, the common difference is d=2 and the number of terms n=10.
-The sum of n terms in the progression can be calculated as follows:
![S_n=0.5n(a_1+a_n)](https://tex.z-dn.net/?f=S_n%3D0.5n%28a_1%2Ba_n%29)
Where
is the sum of the progression's terms.
are the first and last terms of the progression.
#We calculate
as below:
![a_n=a_1+d(n-1)\\\\a_{10}=10+2(10-1)\\\\=28](https://tex.z-dn.net/?f=a_n%3Da_1%2Bd%28n-1%29%5C%5C%5C%5Ca_%7B10%7D%3D10%2B2%2810-1%29%5C%5C%5C%5C%3D28)
#We then substitute to calculate the sum of the terms:
![S_n=0.5n(a_1+a_n)\\\\=0.5\times 10(10+28)\\\\=190](https://tex.z-dn.net/?f=S_n%3D0.5n%28a_1%2Ba_n%29%5C%5C%5C%5C%3D0.5%5Ctimes%2010%2810%2B28%29%5C%5C%5C%5C%3D190)
Hence, 190 chairs are needed for the 10 rows.
Substitution because you need to substitute one of the variables
Multiply without the decimal point, then put it back into the answer.
69 has 0 decimal points 9.2 has 1 therefore the answer will have one decimal point.
multiply 69*92=6348
insert the decimal point and the answer is 634.8