Find and correct the error of the following factor. factor by grouping: 3x² + xy2 – 3xy-y? line 1: = (3x² + xy2)+(-3xy – y? ) line 2: = x(3x + y2) - y(3x – y2) line 3: = (x-y) (3x +y? )

3x² + xy2 – 3xy-y? >> 3x² - xy - y

line 1: = (3x² + xy2)+(-3xy – y?)

ANS 3x² - xy - y 《Correct》

line 2: = x(3x + y2) - y(3x – y2)

ANS 3x² - xy +2y²

line 3: = (x-y) (3x +y?)

ANS 3x² - 2xy - y²

If it incorrect, I'm sorry.

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.

30 miles

step-by-step explanation:

we know that 60 seconds equals 1 minute and 60 minutes 1 hour

44 ft       60 sec     60 min     158400   ft

  *   *   =

1 sec       1 min       1 hour         hour

we know that there are 5280 ft per mile

158400   ft       1 mile         30 miles

  *   =

1   hour               5280 ft     1 hour

so in 1 hour   it can travel 30 miles