Answer:
The probability that he chooses trees of two different types is 30%.
Step-by-step explanation:
Given that a landscaper is selecting two trees to plant, and he has five to choose from, of which three of the five are deciduous and two are evergreen, to determine what is the probability that he chooses trees of two different types must be performed the following calculation:
3/5 x 2/4 = 0.3
2/5 x 3/4 = 0.3
Therefore, the probability that he chooses trees of two different types is 30%.
You can solve this one by adding their rates, but you have to invert the numbers they give you to find the rate. Rate is measured in something per unit of time, and "per" indicates division. So the rates are: 1/3 of an hour (Sally) and 1/6 of an hour (Steve). So add the rates: 1/3 + 1/6 = 1/2. (1/3 is 2/6, and 2/6 + 1/6 = 3/6). Since their combined rate is 1/2 of a room in one hour, it takes them two hours to paint the room.
This answer makes sense: It takes Sally three hours by herself; with Steve's help, she's faster, but not THAT much faster, because he's pretty slow. You can often spot-check word problem answers like this by giving it a common sense once-over. If we came up with four hours, that would clearly be wrong: it should take her LONGER if she's getting help.
Answer:
1-3x+8y
Step-by-step explanation:
Multiply y and 2
Multiply y and 1
The y just gets copied along.
2*y evaluates to 2y
Multiply x and 4
Multiply x and 1
The x just gets copied along.
The answer is x
4*x evaluates to 4x
2*y-4*x evaluates to 2y-4x
The answer is 2y-4x+8
2*y-4*x+8 evaluates to 2y-4x+8
Multiply y and 6
Multiply y and 1
The y just gets copied along.
The answer is y
6*y evaluates to 6y
2y + 6y = 8y
The answer is 8y-4x+8
2*y-4*x+8+6*y evaluates to 8y-4x+8
-4x + x = -3x
The answer is -3x+8y+8
2*y-4*x+8+6*y+x evaluates to -3x+8y+8
8 - 7 = 1
The answer is 1-3x+8y
2*y-4*x+8+6*y+x-7 evaluates to 1-3x+8y
Answer: f=26
Step-by-step explanation: x^2+6x^2+12x+7/x= 26
