Hello from MrBillDoesMath!
Answer:
3
Discussion:
34 + 2x = 40 => subtract 34 from both sides
(34-34) + 2x = 40 - 34 => as (34-34) = 0 and 40-34 = 6
2x = 6 => divide both sides by 2
x = 6/2 = 3
Check the answer:
Does 34 + 2x = 40 if x = 3 ?
Does 34 + 2(3) = 40 ?
Does 34 + 6 = 40 ? YES! so the answer checks.
Thank you,
MrB
Hey there! I'm happy to help.
Let's think of the line segment KM as a road. It starts at point K and ends at M. You start driving from point K and after 4 miles, you have reached point L. The segment KL is equal to 4 because the distance between K and L is 4.
From point L to point M, you drive 11 miles. You are now at the end of the road. We want to find out how long the road is.
From point K to point L, you drove for 4 miles.
Then, from L to M, you drove 11.
We combine these...
11+4=15
The length of KM is 15.
Have a wonderful day! :D
Answer:
70
Step-by-step explanation:
= First term = 
= Common difference = 
= Number of terms = 20
Sum of arithmetic progression is given by
![S=\dfrac{n}{2}[2a_1+(n-1)d]\\\Rightarrow S=\dfrac{20}{2}\times (2\times \dfrac{1}{3}+(20-1)\dfrac{1}{3})\\\Rightarrow S=70](https://tex.z-dn.net/?f=S%3D%5Cdfrac%7Bn%7D%7B2%7D%5B2a_1%2B%28n-1%29d%5D%5C%5C%5CRightarrow%20S%3D%5Cdfrac%7B20%7D%7B2%7D%5Ctimes%20%282%5Ctimes%20%5Cdfrac%7B1%7D%7B3%7D%2B%2820-1%29%5Cdfrac%7B1%7D%7B3%7D%29%5C%5C%5CRightarrow%20S%3D70)
The sum of the first 20 terms of the arithmetic sequence is 70.
(2.5×10⁻⁸)(9×10⁻¹⁰) = 2.5×9×10⁻⁸⁻¹⁰ = 22.5×10⁻¹⁸
= 2.25×10⁻¹⁷
_____
The rules of exponents apply.
... 10^a × 10^b = 10^(a+b)
... 22.5 = 2.25 × 10¹
