After staring at this for a few seconds, I think the equation
![-5\sqrt{10}\cdot\sqrt{15}=[1]\sqrt{[2]}](https://tex.z-dn.net/?f=-5%5Csqrt%7B10%7D%5Ccdot%5Csqrt%7B15%7D%3D%5B1%5D%5Csqrt%7B%5B2%5D%7D)
is asking you to simplify the left hand side so that it has a form matching the right hand side, and [1] and [2] are placeholders. My guess is that they're supposed to be integers.
Notice that



Then multiplying by -5, we have

so I believe [1] = -25, and [2] = 6.
Answer:
the answer is 30/99, which simplifys to 10/33
Step-by-step explanation:
Hope this helps. You always change the denomiter to 99 for repeating decimal. Good luck
Answer: finding slope (-4, 1), (1,-2) : m= -3/5
Answer:
2x^2 y^3
Step-by-step explanation:
so its 2x then squared by 2 then y and squared by 3 all together making 2x^2y^3
Answer:
a) The half life of the substance is 22.76 years.
b) 5.34 years for the sample to decay to 85% of its original amount
Step-by-step explanation:
The amount of the radioactive substance after t years is modeled by the following equation:

In which P(0) is the initial amount and r is the decay rate.
A sample of a radioactive substance decayed to 97% of its original amount after a year.
This means that:

Then



So

(a) What is the half-life of the substance?
This is t for which P(t) = 0.5P(0). So







The half life of the substance is 22.76 years.
(b) How long would it take the sample to decay to 85% of its original amount?
This is t for which P(t) = 0.85P(0). So







5.34 years for the sample to decay to 85% of its original amount