(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.
The equation given in the question has one unknown variable in the form of "x" and only one equation is required to find the value of the unknown variable. So it is absolutely possible to find the exact value of "x".
6(-3 - x) - 2x = 14
-18 - 6x - 2x = 14
-18 - 8x = 14
Multiplying both sides of the equation by -1 we get
8x + 18 = - 14
Dividing both sides by 2 we get
4x + 9 = - 7
4x = - 7 - 9
4x = - 16
x = - 16/4
= - 4
So the value of "x" comes out to be equal to - 4. I hope the procedure is clear enough for you to understand.
I Think The integers are:
27,28,29 & 30
The answer would be: -a - 5
30=1/2(12)(h)
30=(6)(h)
h=5