Answer: 2(x-5y)(2x+y) ?
Step-by-step ex5planation:
The answer is one over thirty two to the seventh power
Difference in doughnuts = 50 - 40 = 10
Difference in money = 15 + 5 = 20
20 ÷ 10 = $2
Each doughnut costs $2
<em>Check:</em>
40 x 2 + 5 = $85
50 x 2 -15 = $85
Ravi has $85 at first.
Each doughnut costs $2
Answer:
Time machine one = 3.56
Time machine two = 4.56
Step-by-step explanation:
Let machine 2 do the job in x hours
Let machine 1 do the job in x - 1 hours.
The general formula for this problem is
Time = A*B/(A + B)
Givens
Time = 2 hours
B = x hours alone
A = x - 1 hours alone.
#################
x *( x - 1)
======= = 2
(x + x - 1)
(x^2 - x)/(2x - 1) = 2
x^2 - x = 2(2x - 1)
x^2 - x = 4x - 2
x^2 - 5x + 2 = 0
a = 1
b = - 5
c = 2
This gives 2 roots
x = 4.56
x = 0.43
The second root will not work because when 1 is subtracted from 0.43 the time give will be minus, which won't work.
Time for machine 2 is 4.56
The time for machine 1 is 3.56
Check
(A * B)/(A + B) = 2
A = 4.56
B = 3.56
Time = 4.56*3.56/(4.56 + 3.56)
Time = 16.2336/(8.12)
Time = 1.9992
The rounding error in the check comes from the rounding error in the times.
Slope: (y2-y1)/(x2-x1)
(3-3)/(2-10) = 0/-8 = 0
The slope is 0
