Matthew earns extra money by doing odd jobs for his neighbors. He charges a flat fee of $20 plus $7 per hour for each job. If he earned $90 for a job he did last week, how many hours did he work?

10 hours

Step-by-step explanation:

ok so we know he is getting payed $20 + $7 every hour so what i would do is keep the multiply the 7 till you get 70 so thats 7x10=70 and 70+20=90 so he worked for 10 hours last week :)  i hope this helps, i tried my best to explain it

t = 3

step-by-step explanation:

put t = 3 in this expression :

(3²-1)(3²-2)(3² - 3)(3² - 4) = 8×7×6×5 = 56×30 = 1680