Sergio's internet provider charges its customers $9 per month plus 4¢ per minute of on-line usage. sergio received a bill from the provider covering a period and was charged a total of $81.40. how many minutes did he spend on-line during that period? (round to the nearest whole minute, if necessary.)

answer: 1 + 1 = 11

step-by-step explanation:

the correct answer option is (2x-3)(2x+3).

step-by-step explanation:

we are given the following expression and we are to factorize it:

we are to find such factors that when multiplied they give a result of 36 (9 x 4 = 36) and when added they give a result of 0.

the two such factors of 36 are negative six and postive six.

factorizing the given expression to get:

therefore, the correct factorization of is (2x-3)(2x+3).