Answer: -a2 - 2ab - b2 + 25 =
-1 • (a2 + 2ab + b2 - 25)
Final result :
-a2 - 2ab - b2 + 25
Step-by-step explanation:
Answer:
60km
Step-by-step explanation:
we multiply 30 with 2 and we get the answer as 60km in two hours.
Let's factor the top and the bottom.
Top factors 4x + 20 = 4(x + 5)
Bottom x^2 + 2x - 15 = (x + 5)(x - 3)
The gcf is the largest value that will go into both the top and the bottom. In our problem the ONLY thing that will go into top and bottom is x + 5 so that is your GCF. (c)
Procedure:
1) calculate the number of diferent teams of four members that can be formed (with the ten persons)
2) calculate the number of teams tha meet the specification (two girls and two boys)
3) Divide the positive events by the total number of events: this is the result of 2) by the result in 1)
Solution
1) the number of teams of four members that can be formed are:
10*9*8*7 / (4*3*2*1) = 210
2) Number of different teams with 2 boys and 2 girls = ways of chosing 2 boys * ways of chosing 2 girls
Ways of chosing 2 boys = 6*5/2 = 15
Ways of chosing 2 girls = 4*3/2 = 6
Number of different teams with 2 boys and 2 girls = 15 * 6 = 90
3) probability of choosing one of the 90 teams formed by 2 boys and 2 girls:
90/210 = 3/7
