The general way to work this out is to solve the general expression for
the remaining quantity versus half-life, using logarithms. But that's not
necessary with these numbers.
Look at the numbers:
-- 3 mg is 1/4 of 12 mg.
-- 1/4 is the product of (1/2) x (1/2).
-- So the 3 mg is what's left of 12 mg after 2 half-lives.
The 26 minutes must be two half-lives.
-- The half-life of that substance is 26/2 = <em>13 minutes</em>.
Go Maggie !
Would this work? Hope it helps
Answer:
Step-by-step explanation:
2)
a) elimination method
b) substitution method
c) substitution method
For the first part we can elimate the y variable by subtracting the equations. We can then find the value of x.
For the second part we can substitute y as 2x+5 in the second equation and solve for x.
For the third part we can substitute y as 4x+3 in the first equation and solve for x.
3)
The answer to this question is ....... a) 11
They are used for making the sides of a triangle into a ratio. Sine is opposite of the angle divide by the hypotenuse, cosine is adjacent divided by the hypotenuse, and tangent is the opposite divided by the adjacent. Sine is the y-component, cosine is the x-component, and tangent is the ratio of sine/cosine or can also be considered the slope.
