The total scores of the x students from class A can be calculated by multiplying x and the average which is equal to 85. That is 85x.
In similar manner, we are able to find for the total scores of the students from Class B. That would be, 90y.
Combining the scores, the new average then becomes 88. This is equal to,
(85x + 90y) / (x + y ) = 88
Cross-multiplying,
85x + 90y = 88x + 88y
Combine all the x's and y's in each side of the equation.
85x - 88x = 88y - 90y
Combining terms,
-3x = -2y
The ratio is obtained through the step below,
-3x/-3y = -2y/-3y
x/y = 2/3
Thus, the ratio is 2/3.
9.
By the Segment Addition Postulate, SAP, we have
XY + YZ = XZ
so
YZ = XZ - XY = 5 cm - 2 cm = 3 cm
10.
M is the midpoint of XZ=5 cm so
XM = 5 cm / 2 = 2.5 cm
11.
XY + YM = XM
YM = XM - XY = 2.5 cm - 2 cm = 0.5 cm
12.
The midpoint is just the average of the coordinate A(-3,2), B(5,-4)

Answer: M is (1,-1)
You'll have to plot it yourself.
13.
For distances we calculate hypotenuses of a right triangle using the distnace formula or the Pythagorean Theorem.

Answer: AB=10
M is the midpoint of AB so
Answer: AM=MB=5
14.
B is the midpoint of AC. We have A(-3,2), B(5,-4)
B = (A+C)/2
2B = A + C
C = 2B - A
C = ( 2(5) - -3, 2(-4) - 2 ) = (13, -10)
Check the midpoint of AC:
(A+C)/2 = ( (-3 + 13)/2, (2 + -10)/2 ) = (5, -4) = B, good
Answer: C is (13, -10)
Again I'll leave the plotting to you.
Answer:
121π
Step-by-step explanation:
The formula for a circle is πr^2. But if given a diameter instead of radius, you simply divide by 2 because radius is half of a diameter.
Radius of this circle is 11 because you divide 22 by 2.
Then you follow the formula. 11^2=121.