Answer:
19
Step-by-step explanation:
"You stupid"
"No Im not"
"Whats 9+10"
"21"
"You stupid"
Answer: D. (4,3)
The x coordinates of A and B are 9 and -1 in that order. Add them up to get 9+(-1) = 9-1 = 8. Then divide by two to end up with 8/2 = 4. The midpoint has an x coordinate of 4.
Repeat for the y coordinates. Add them up: 8+(-2) = 8-2 = 6. Then divide by two: 6/2 = 3. The midpoint has an y coordinate of 3.
Those two coordinates pair up to get (x,y) = (4,3) which is the midpoint of segment AB.
The answers and explanations are in the picture
Answer:
The chemist needs to add 400mL of 40% solution.
Step-by-step explanation:
The equation
gives the percent concentration 
of the final mixture, when 
mL of the 40% solution are added.
Now we are asked, how many milliliters of the 40% solution should the chemist add to get final percent concentration 
; this is just a matter of solving the equation
and we solve it the following way:
Thus, the chemist needs 400mL of 40% solution to get 30% concentration of the final mixture.
