Jon completed a job for 156 dollar, it  took him seven   hours   longer   than   he   expected   and   so he earned $14 an hour less than he anticipated. How long did Jon expect the job to take. По алгебре көмек керек ​

6/(х-1)+6/(х+1)=4.5

6х+6+6х-6-4,5х²+4,5=0  *2

9х²-24х-9=0

д=576+324=900

х=(24±30)/18=3; -1/3

отв: 3 км/ч

sin 187= -0.9  < 0

cos 215= 0.1  >   0

tg 80 =  9 > 0

сумма: 27+22=49

разность: 27-22=5

49x5=245

12х-(3х-5)+(9х-3)=12х-3х+5+9х-3=2

4(х+0,2)=5х-3,8

4х+0,8=5х-3,8

4х-5х=-3,8-0,8

-х=-4,6

х=4,6