Answer:
y represents the pages, while x represents the minutes. for every y, there is 9/10 x, therefore the equation is y=9/10x
372.733 i tjink thats the asnwer
Answer:
x = -2
y = 5
Step-by-step explanation:
Given two equations
1. 7x + 10y = 36
2. y = 2x + 9
Substitute 2x + 9 for y in equation 1.
We have
7x + 10y = 36
7x + 10(2x + 9) = 36
Distribute 10 into (2x + 9)
We have
7x + 10 x 2x + 10 x 9 = 36
7x + 20x + 90 = 36
27x + 90 = 36
Subtract 90 from both sides to eliminate 90 on the left side
27x + 90 - 90 = 36 - 90
27x = -54
Divide both sides by 27 to isolate x
27x/27 = -54/27
x = -2
Now substitute -2 into either equation to get y
Using equation 2, we have
y = 2x + 9
= 2 x -2 + 9
= -4 + 9
= 5
x = -2
y = 5
Check
7(-2) + 10(5) = 36
Compute the derivative dy/dx using the power, product, and chain rules. Given
x³ + y³ = 11xy
differentiate both sides with respect to x to get
3x² + 3y² dy/dx = 11y + 11x dy/dx
Solve for dy/dx :
(3y² - 11x) dy/dx = 11y - 3x²
dy/dx = (11y - 3x²)/(3y² - 11x)
The tangent line to the curve is horizontal when the slope dy/dx = 0; this happens when
11y - 3x² = 0
or
y = 3/11 x²
(provided that 3y² - 11x ≠ 0)
Substitute y into into the original equation:
x³ + (3/11 x²)³ = 11x (3/11 x²)
x³ + (3/11)³ x⁶ = 3x³
(3/11)³ x⁶ - 2x³ = 0
x³ ((3/11)³ x³ - 2) = 0
One (actually three) of the solutions is x = 0, which corresponds to the origin (0,0). This leaves us with
(3/11)³ x³ - 2 = 0
(3/11 x)³ - 2 = 0
(3/11 x)³ = 2
3/11 x = ³√2
x = (11•³√2)/3
Solving for y gives
y = 3/11 x²
y = 3/11 ((11•³√2)/3)²
y = (11•³√4)/3
So the only other point where the tangent line is horizontal is ((11•³√2)/3, (11•³√4)/3).
Answer:
x = 162 cards need to be dealt with
Step-by-step explanation:
Given:
- Estimation of likelyhood of next card to be queen, a king, or an ace:
( 64 - 0.2*x ) / ( 208 - x )
Find:
For what values of x is this likelihood greater than 70%?
Solution:
- Use the likely-hood estimation relation and set up the inequality as follows:
( 64 - 0.2*x ) / ( 208 - x ) > 0.7
( 64 - 0.2*x ) > 0.7*( 208 - x )
64 - 0.2*x > 145.6 - 0.7*x
0.5*x > 81.6
x > 163.2
- It would require 162 cards to be dealt with for the probability of next card being queen, a king, or an ace is greater than 70%
