Answer:
Yes. You can make a tree diagram with each subject at the top and the periods as the branches or with the periods at the top and each subject as a branch. Both ways provide the same number of outcomes, 18
Step-by-step explanation:
Add 2 to both sdies
now if we can facor, then if
xy=0 then x and/or y=0
note:xy=x times y and x(y) =x times y
x^2+3x+2=0
what 2 number multiply to get 2 and add to get 3
the numbers are 2 and 1
(x+2)(x+1)=0
set them to zero
x+2=0
subtract 2
x=-2
x+1=0
subtract 1
x=-1
x could be -1 or -2
x=-2, or -1
1turn = 360 half a turn is 180
360+180=540