Answer:
about 15 hours
Step-by-step explanation:
You want to find t such that N(t)=200. Fill in the equation with that information and solve for t.
200 = 400/(1 +399e^(-0.4t))
1 +399e^(-0.4t) = 400/200 = 2 . . . . . multiply by (1+399e^(-0.4t))/200
399e^(-0.4t) = 1 . . . . . . . . . . . . . . . . . . subtract 1
e^(-0.4t) = 1/399 . . . . . . . . . . . . . . . . . .divide by 399
-0.4t = ln(1/399) . . . . . . . take the natural log
t = ln(399)/0.4 ≈ 14.972 . . . . . . . divide by -0.4, simplify
Rounded to tenths, it will take 15.0 hours for half the people to have heard the rumor.
The least common denominator would be 2x^2
that is because you would have to multiply the first fraction by 2x
but you can't just somehow simplify 2x^2, it wouldn't be right
4/x * -4/2x^2
2x*4/(2x*x) * -4/2x^2
8x /2x^2 * -4/2x^2
Then you would complete it
Hope this helps :)
Answer:
50 miles per hours
Step-by-step explanation:
400 miles per 8 hours is the same as
200 miles for 4 hours which is the same as
100 miles for 2 hours which is still the same as
50 miles per hour
I just divided each one by two until I reached the unit rate
Answer:
Step-by-step explanation:
take lcm of (2x-1)(x+2)
lcm=(2x-1)(x+2)
=2(x+2)-1(2x-1)/(2x-1)(x+2)
=(2x+4)-(2x-1)/(2x(x+2)-1(x+2)
=2x+4-2x+1/2x^2+4x-x+2
=4+1/2x^2+3x+3
=5/2x^2+3x+3
The standard form is 24,000,011
