Answer:
21
Step-by-step explanation:
Answer:
-180√3
Step-by-step explanation:
3√10 x - 6√30
= 3x-6 x -√10 x √30
= -18 x√300
= -18 x 10√3
= -180√3
So the formula for area of a triangle is A= 1/2 base x height. SO you do 20 x 30 you get 600. 600/ 2 = 300 so 300 km squared.
Answer:
Coordinates of B is (3,-4)
Step-by-step explanation:
You multiply -2 by 2 to get -4 and then create the equation
then you substitue -7 for +7 and add +7 to -4 which gives you 3 (x coordinate of B)
You multiply -1 by 2 to get -2 and then create the equation
then you subtract 2 by -2 which gives you -4 (y coordinate of B)
To check your answer use the midpoint formula 
which will give you the midpoint (-2,-1)