Joyce waited 50 minutes waiting for the train
Step-by-step explanation:
divide 60 by 3 cause 3 quarters of an hour is 3/4 then you wanna take half an hour and add that (30 mins) getting 50 minutes
I'm assuming that when you say expanded form, you mean broken down into ones, tens, hundres and so forth.
so, 1203=1000+200+3
Answer:
The correct answer is:
Between 600 and 700 years (B)
Step-by-step explanation:
At a constant decay rate, the half-life of a radioactive substance is the time taken for the substance to decay to half of its original mass. The formula for radioactive exponential decay is given by:
First, let us calculate the decay constant (k)
Next, let us calculate the half-life as follows:
Therefore the half-life is between 600 and 700 years
This is a system of equations. You can solve it by substitution or elimination. I'm going to use substitution x - 2y = -4.5; add 2y to each side x - 2y + 2y = -4.5 + 2y; simplify x = 2y - 4.5 2(2y - 4.5) + 3y = 12 4y - 9 + 3y = 12 7y - 9 = 12 7y - 9 + 9 = 12 + 9 7y = 21 y = 3 <--------first answer x - 2y = -4.5 x - 2(3) = -4.5 x - 6 = -4.5 x -6 + 6 = -4.5 + 6 x = 1.5 <--------second answer Check: 2(1.5) + 3(3) = 12? 3 + 9 = 12? 12 = 12; It checks 1.5 - 2(3) = -4.5? 1.5 - 6 = -4.5? -4.5 = -4.5; It checks x = 1.5 and y = 3 <-----------Final Answer
Answer:
x=3
Step-by-step explanation:
3x+5=14
-5 -5
3x=9
/3 /3
x=3
