time * rate = distance
Downstream 4 * x = 4(x)
Upstream 6 * x - 2 = 6(x - 2)
distance downstream = distance upstream:
4(x) = 6(x - 2)
4x = 6x - 12
-2x = -12
x = 6
Distance Upstream: 4x = 4(6) = 24
Distance Upstream: 6(x - 2) = 6(6 - 2) = 6(4) = 24
Total distance traveled is Upstream + Downstream = 24 + 24 = 48
Answer: 48 miles
Answer:
x = 37 y = 12
Step-by-step explanation:
Let x be one number
Let y = other number
x+y = 49
x-y = 25
Add the equations together
x+y = 49
x-y = 25
---------------
2x = 74
Divide by 2
2x/2 = 74/2
x =37
x+y = 49
37+y = 49
Subtract 37 from each side
37+y-37 = 49-37
y = 12
Answer:
Step-by-step explanation:
we can use the trigonometric function in a right triangle
cos x = adjacent side to the angle /hypothenuse
cos 36°= x/10 ; multiply both sides by 10
10 * cos 36° = x ; make sure your calculator mode is in degrees
8.1 = x
Y = -4/5 + 7, the 7 is the slope intercept and the -4/5 is the slope
Answer:
x = 10 cm, y = 5 cm gives a minimum area of 300 cm^2.
Step-by-step explanation:
V= x^2y = 500
Surface area A = x^2 + 4xy.
From the first equation y = 500/x^2
So substituting for y in the equation for the surface area:
A = x^2 + 4x * 500/x^2
A = x^2 + 2000/x
Finding the derivative:
dA/dx = 2x - 2000x^-2
dA/dx = 2x - 2000/x^2
This = 0 for a minimum/maximum value of A, so
2x - 2000/x^2 = 0
2x^3 - 2000 = 0
x^3 = 2000/ 2 = 1000
x = 10
Second derivative is 2 + 4000/x^3
when x = 10 this is positive so x = 10 gives a minimum value of A.
So y = 500/x^2
= 500/100
= 5.
