Answer:
a) 
b) -14
c) -3
d) -96
Step-by-step explanation:
a) The parenthesis indicate multiplication.
b) Minus and plus gives subtraction, and the sign you put behind the number is the sign of the largest number you have (in this case it's 21 since we ignore the -)
c) They already have common denominators, all that's left is to do 
d) The parenthesis indicate multiplication.
Good luck!
Answer:
Umm is this a problem or like-
Step-by-step explanation:
Umm is this a problem or like-
Answer:
They do not intersect, but are coplanar
Step-by-step explanation:
Parallel lines are coplanar (they lie in the same plane) and never intersect.
Answer:
-57.29
Step-by-step explanation: