Answer:
(9 x - 7 y) (9 x + 7 y)
Step-by-step explanation:
Factor the following:
81 x^2 - 49 y^2
Hint: | Express 81 x^2 - 49 y^2 as a difference of squares.
81 x^2 - 49 y^2 = (9 x)^2 - (7 y)^2:
(9 x)^2 - (7 y)^2
Hint: | Factor the difference of two squares.
Factor the difference of two squares. (9 x)^2 - (7 y)^2 = (9 x - 7 y) (9 x + 7 y):
Answer: (9 x - 7 y) (9 x + 7 y)
Answer:
13
Step-by-step explanation:
count across and then down
It's just consistent, man. hope that helps
Answer:
Jeans-$19.95
Step-by-step explanation:
The expression for each individual's purchase can be expressed as:

We make j the subject in equation i then substitute in ii:

Hence, it costs $19.95 per pair of jeans and $12.50 per shirt pair.
Answer:
= −0.26
= 0.4219
Step-by-step explanation:
Given:
Sample1: 98.1 98.8 97.3 97.5 97.9
Sample2: 98.7 99.4 97.7 97.1 98.0
Sample 1 Sample 2 Difference d
98.1 98.7 -0.6
98.8 99.4 -0.6
97.3 97.7 -0.4
97.5 97.1 0.4
97.9 98.0 -0.1
To find:
Find the values of
and 
d overbar (
) is the sample mean of the differences which is calculated by dividing the sum of all the values of difference d with the number of values i.e. n = 5
= ∑d/n
= (−0.6 −0.6 −0.4 +0.4 −0.1) / 5
= −1.3 / 5
= −0.26
s Subscript d is the sample standard deviation of the difference which is calculated as following:
= √∑(
-
)²/ n-1
=
√ 
= √ (−0.6 − (−0.26
))² + (−0.6 − (−0.26))² + (−0.4 − (−0.26))² + (0.4 −
(−0.26))² + (−0.1 − (−0.26))² / 5−1
=
= 
= 
= 0.4219
= 0.4219
Subscript d represent
μ
represents the mean of differences in body temperatures measured at 8 AM and at 12 AM of population.