To estimate, round 3102 to 3100
round 1-10 to 2500
1-70 to 2100
1-80 to 2900
2900+2100+2500+3100=10600mi
Yes it is reasonable because you add and subtract numbers when estimating, however it is not exact
the answer this question is h=20 ft
Answer:
The sum of reciprocals is 2/3.
You don't need complex numbers to solve this, but if you try to find a and b you will need complex numbers.
Step-by-step explanation:
a+b = 2
a*b = 3
1/a + 1/b = x
(a*b)*(1/a + 1/b) = (a*b)x
b + a = (a*b)(x)
2 = 3x
x = 2/3
b = 2 - a
a*(2 - a) = 3
-a^2 + 2a = 3
-a^2 + 2a - 3 = 0
a^2 - 2a + 3 = 0
let's solve the quadratic equation
a^2 - 2a + 3 = a^2 - 2a + 1 + 2 = (a - 1)^2 + 2 = 0
(a - 1)^2 = -2
these options correspond to a and b from the original question.
<h3>
Answer: 15 hours (choice D)</h3>
================================================
Work Shown:
(6 hours)/(8 trees) = (x hours)/(20 trees)
6/8 = x/20
6*20 = 8*x ... cross multiply
120 = 8x
8x = 120
x = 120/8
x = 15
It takes him 15 hours to plant 20 trees.
Answer:
Step-by-step explanation:
<u>Property of regular polygons:</u>
- Sum of Interior Angles = (n−2) × 180°, where n is number of sides
<u>In our case we have:</u>
- 158.8×n = (n - 2)×180
- 180n - 158.8n = 360
- 21.2n = 360
- n = 360/21.2
- n = 17