Answer:
ionno my brein is small
Step-by-step explanation:
sOrRy
Answer:
8x² - 15y² + xy
Step-by-step explanation:
(4x + 5y) (2x - 3y) + 3xy
multiplying the terms in brackets
(4x) (2x - 3y) + (5y) (2x - 3y) + 3 xy
multiplying with each terms inside the bracket
(4x)(2x) - (4x) (3y) + (5y) (2x) - (5y) (3y) + 3xy
doing the product each of the pair of terms
8x² - 12xy + 10xy - 15y² + 3xy
taking the sum of terms with coefficient "xy"
8x² - 15y² -2xy + 3xy
8x² - 15y² + xy
Here is dependence between scores and x-values:
where 
is the mean, 
is standard deviation and i changes from 1 to 2.
1. When i=1, 
then
2. When i=2, 
then
Now solve the system of equations:
Subtract first equation from the second:
Then
Answer: the mean is 62, the standard deviation is 20.
Answer:-2,4 is the answer
Step-by-step explanation:
