You turn 85% into a decimal
then multiply the decimal by the main number.
420x.85=357.
so 85% of 420 is 357
Answer:
x = 25
Step-by-step explanation:
49 - 25 = 25
(126) times (1/2 to the x/11 power) = 15% times 126
(1/2) to the x/11 power = 0.15
Take the log of both sides :
(x/11) times log(1/2) = log(0.15)
Multiply both sides by 11 :
'x' times log(1/2) = 11 x log(0.15)
Divide both sides by " log(1/2) " :
x = 11 x log(0.15)/log(1/2) = <em><u>30.107 years</u></em> (rounded)
That's the time it takes for <em><u>any-size</u></em> sample of this substance
to decay to 15% of its original size.
Answer:
the answer for this problem is x^2+2x-15
Step-by-step explanation:
(x+5)(x-3)
x(x-3)+5(x-3)
x^2-3x+5(x-3)
x^2-3x+5x-15
=x^2+2x-15
Answer:
6973568802
Step-by-step explanation:
I memorized the equation: A(n) = A(1)*d^(n-1).
You can plug into the equation A(21) = 2*3^20, which can be solved to 6973568802. (I solved this step through a calculator by finding 3^20, then multiplying that by 2 to get 6973568802.
Hope this helps!
