Answer: x-18=-13
5
4 3/5
Step-by-step explanation:
Mean = (total of contributors) / (number of contributors)
For the 6 people in the room, you have
40 = (total of contributors) / 6
(total of contributors) = 6*40 = 240
A 60-year-old left the room, decreasing the total of contributors by 60.
(new total of contributors) = (total of contributors) - 60
(new total of contributors) = 240 - 60 = 180
Then the new mean is
(new mean) = (new total of contributors) / (new number of contributors)
(new mean) = 180 / 6 = 36
The mean age of the remaining 5 people is 36.
Answer:
960 ft^2
Step-by-step explanation:
There are 9 surfaces forming the solid.
5 of them are congruent squares and 4 of them are congruent triangles.
area of square = (side)^2
area of triangle = (base)(height)/2
total surface area = 5 * area of square + 4 * area of triangle
A = 5 * (12 ft)^2 + 4 * (12 ft * 10 ft)/2
A = 5 * 144 ft^2 + 4 * 60 ft^2
A = 720 ft^2 + 240 ft^2
A = 960 ft^2
5x + 2y = 6
3x + y = 4....multiply by -2
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5x + 2y = 6
-6x - 2y = -8 (result of multiplying by -2)
-------------add
-x = -2
x = 2
5x + 2y = 6
5(2) + 2y = 6
10 + 2y = 6
2y = 6 - 10
2y = -4
y = -4/2
y = -2 <=== here it is
