7 divided by 342

7 divided by 342

The third power of 7 is 343, so the 2013 power of 7 is the 671 power of 343, that is, (342 + 1) ^ 671, because the formula can be expanded into the power forms of 342, and there is one more at last, so the remainder is 1 after dividing by 342,

1 out of 7 + 2 out of 7 + 3 out of 7 = 2 out of 7 * () = () 2.19 out of 1 + 2 out of 19 + 3 out of 19 + 4 out of 19 + 5 out of 19 = 3 out of 19 * () = () 3
1 / 11 + 2 / 11 + 3 / 11 + 4 / 11 + 5 / 11 + 6 / 11 + 7 / 11 = 4 / 11 * () = () fill in the blanks,

1 / 7 + 2 / 7 + 3 / 7 = 2 / 7 * (3) = (6 / 7)
1 of 19 + 2 of 19 + 3 of 19 + 4 of 19 + 5 of 19 = 3 of 19 * (5) = (15 of 19)
3.1/11+2/11+3/11+4/11+5/11+6/11+7/11=4/11*（7 ）=（28/11 ）

5 of 7 + 3 of 14 / 3 of 4 + 2 of 3 * 3 of 4 = 2 of 15 / (19 of 21 + 3 of 7) * 1 of 2=
What's the formula

5 of 7 + 3 of 14 / 3 of 4 + 2 of 3 * 3 of 4
=5/7+2/7+1/2
=1+1/2
=1.5
2 / 15 / (19 / 21 + 3 / 7) * 1 / 2
=2/15÷4/3×1/2
=1/10×1/2
=1/20

For a job, it takes 15 hours for Party A to do it alone, and 12 hours for Party B to do it alone. If Party A does it for one hour first, and Party B does it for four hours alone, the rest of the work will be done by two people. Question: how many more hours can we complete the task?
Quick. I'm in a hurry. The equation of first degree with one variable

The task can be completed in X hours
1/15+1/12x4+(1/15+1/12）x=1
1/15+1/3+3/20x=1
3/20x=3/5
x=4