Answer:
The system of equations is
Step-by-step explanation:
Let
x ----> the number of minutes of calling time
y ----> the monthly cost of the calling plan
we know that
The linear equation in slope intercept form is equal to

where
m is the slope
b is the y-intercept
In this problem
Plan A

substitute
----> equation A
Plan B

substitute
----> equation B
therefore
The system of equations is
Answer:
19
Step-by-step explanation:
If you go backwards you can to 58+37, which is equal to 95, and the opposite of multiplying is dividing, so If you divide 95 by 5, you get 19
Answer:
0.9995
Step-by-step explanation:
10% = 0.10
1 - 0.10 = 0.9
n = number of light bulbs = 7
we calculate this using binomial distribution.
p(x) = nCx × p^x(1-p)^n-x
our question says at most 4 is defective
= (7C0 × 0.1⁰ × 0.9⁷) + (7C1 × 0.1¹ × 0.9⁶) + (7C2 × 0.1² × 0.9⁵) + (7C3 × 0.1³ × 0.9⁴) + (7C4 × 0.1⁴ × 0.9³)
= 0.478 + 0.372 + 0.1239 + 0.023 + 0.0026
= 0.9995
we have 0.9995 probability that at most 4 light bulbs are defective.
Given:
The edge length of a cube is changing at a rate of 10 in/sec.
To find:
The rate by which cube's volume changing when the edge length is 3 inches.
Solution:
We have,

We know that, volume of cube is

Differentiate with respect to t.

Substituting
and a=3, we get



Therefore, the volume increased by 270 cubic inches per sec.
Answer:
length = 9 units
Step-by-step explanation:
l = length
n - 6 = width
A = n(n - 6)
A = n² - 6n
27 = n² - 6n
n² - 6n - 27 = 0
(n + 3)(n - 9) = 0
n = -3, n = 9
length must be 9 because it cannot be a negative value