Question

PLEASE HELLLLLPPPPP MEEEE!!!!!

Answer 1

Answer: 480 acres

Step-by-step explanation:

let x = the number of days required to finish the job.

let y = number of acres that had to be cleaned.

without the new machine, the formula would be:

80x = y

that means cleaning 80 acres per day * x days will equal y acres that are cleaned.

with the new machine, the formula would be:

90(x-1) + 30 = y

that means cleaning 90 acres per day for one less day and then cleaning 30 acres on the last day will equal y acres that are cleaned.

so you have 2 equations.

80x = y

90(x-1) + 30 = y

replace y in the second equation with the value of y from the first equation gets you:

90(x-1) + 30 = 80x

solve for x to get:

x = 6

what this means is:

80 acres a day for 6 days will equal 480 acres that are cleaned.

90 acres a day for 5 days and then 30 acres on the last day will equal 480 acres that are cleaned.

with the old machine we are looking at:

80 + 80 + 80 + 80 + 80 + 80 = 480.

with the new machine we are looking at:

90 + 90 + 90 + 90 + 90 + 30 = 480.

looks like they had to clean 480 acres.