Solution :
It is given that a psychologist wants to determine the difficulty of the task influences on the estimate of how long people spend working on it.
Now we have to describe a experiment by using a completely randomized design and learn the effect of the difficulty on the estimated time is by randomly assigning 15 students to a Group 1 of easy mazes and other 15 students to the second group 2 of hard mazes. And then we compare the time estimates of the two groups.
The answer is the first option, <-20, -42>.
We can find this by first finding what -2u would equal by multiplying <5, 6> by -2. This gives us <-10, -12>.
Then we need to find out what 5v is equal to, by multiplying <-2, -6> by 5 to get <-10, -30>.
Now that we know what -2u and 5v are, we can substitute them into the equation and get
<-10, -12> + <-10, -30>, which we can split up into -10 - 10 = -20, and -12 - 30 = -42, so your final answer is <-20, -42>.
I hope this helps!
First, we want to find the GCF of 15 and 21, which is 3. Now we do 15 divided by 3 and 21 divided by 3, which gives us 5 and 7. To rewrite the expression, we take the GCF and put it on the outside of the parenthesis. Inside the parenthesis, we put 5 + 7. So it'll look like this:
3(5 + 7)
