1) its number 2. 30x^7y^4
Answer:
x^2y^2 +9xy^2-xy-27y-6
Step-by-step explanation:
(xy+9y+2) (xy-3)
Each term of second bracket will be multiplied with the terms of first bracket
= xy(xy+9y+2) -3(xy+9y+2)
= x^2y^2+9xy^2+2xy-3xy-27y-6
=x^2y^2+9xy^2-xy-27y-6
It has a bunch of zeroes after the five so it is rounded unless you want to go to .18
Answer:
The 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).
Step-by-step explanation:
The (1 - <em>α</em>)% confidence interval for the difference between population means is:

The information provided is as follows:

The critical value of <em>z</em> for 98% confidence level is,

Compute the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 as follows:


Thus, the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).