collect the like terms:
Solution: x^2-5xy+4y
P.S
get the photo math app. :)
Hope that helps.
If b is in the first position then c can be in any 1 of the remaining 6 positions.
If we start with ab then the letter c can be in any one of 5 positions and if we have aab there are 4 possible positions for c and so on.
So the total number of possible sequences where b comes first = 6+5+4+3+2+1 = 21.
The same argument applies when c comes before b so that gives us 21 ways also.
So the answer is 2 *21 = 42 different sequences.
A more direct way of doing this is to use factorials:-
answer = 7! / 5! = 7 * 6 = 42.
( We divide by 5! because of the 5 a's.)
"Will is twice as old as Jill."
Jill's age . . . . . J
Will's age . . . . 2J .
"Three years ago . . .
Jill's age then . . . . . J - 3
Will's age then . . . . 2J - 3
". . . Jill's age then was 2/5 of Will's age then."
J - 3 = (2/5) (2J - 3)
Multiply
each side by 5 : 5J - 15 = 2 (2J - 3)
Divide
each side by 2 : 2.5 J - 7.5 = 2J - 3
Subtract 2J
from each side: 0.5 J - 7.5 = -3
Add 7.5
to each side: 0.5 J = 4.5
Multiply
each side by 2 : J = 9
Jill is 9 y.o. now.
Will is 18 y.o. now.
Answer: 0.00102%
Step-by-step explanation:
Given : Human body temperatures are normally distributed with a mean of
and a standard deviation of 
A hospital uses
as the lowest temperature considered to be a fever.
Let x be the random variable that represents the human body temperatures.

For x= 100.6, 
Using normal distribution table for z-values for right-tailed area ,
P(x>100.6)=
Hence, the required probability = 0.00102%
Answer:
y = 0.3X + 18.3
Step-by-step explanation:
Given that data :
x = year ;
y = trunk diameter, in inches
Year ________trunk diameter
1 __ 18.6
3 __ 19.2
5 __ 19.8
7 __ 20.4
9 ___21.0
11 __ 21.6
13 __ 22.2
Using the linear regression calculator :
The linear equation obtained is :
y = 0.3X + 18.3
Where ;
Slope = 0.3 ; intercept, c = 18.3