Answer:
1370
Step-by-step explanation:
<h3>Given</h3>
- AP with d= 7 and a₂₂ = 149
<h3>To find</h3>
<h3>Solution</h3>
<u>First, let's get the value of the first term:</u>
- aₙ = a + (n-1)d
- a₂₂ = a + 21d
- 149 = a + 21*7
- a = 149 - 147
- a= 2
<u>Next, let's find the sum of the first 20 terms</u>
- Sₙ = 1/2n(2a+ (n-1)d)
- S₂₀ = 1/2*20(2*2 + 19*7) = 10(4 + 133) = 10*137 = 1370
<u>Answer is</u> 1370
-3|x+4|+16=7
-3|x+4|=7-16
-3|x+4|=-9
|x+4|=3
x+4=3
x+4=-3
x=-1
x=-7
X1=-7 X2=-1
Answer:
2520 patterns
Step-by-step explanation:
In 'n' 10! ways, books can be arranged. But, there are also 5! permutation of blue books 'n1', 2! permutation of identical green books 'n2', and 3! permutation identical black books 'n3'.
Therefore, for non identical arrangements:

= 2520
Therefore, the books can be arranged on a shelf in 2520 patterns
Answer:
<u>Acute Angle</u>
Step-by-step explanation:
<u>Obtuse Angle</u> is greater than 90 degrees
<u>Right Angle</u> is exactly 90 degrees
<u>Acute Angle</u> is less than 90 degrees