Supposing we begin with n=1, the first few terms of this arith sequence are
5, 1, -3, -7, and so on. 4 is the common difference.
People moved to the cities to escape war. Some people had left the countryside to work in the arms industry and some had left for Rome looking for subsistence. Rome became the most populous city in Europe and West Asia.
The old mean was 51 now the mean is 42.33... (round that to 42) 51 - 42 = 9
From the Special Triangle Theorem, the hypotenuse is equal to the side lengtht times the Sqrt(2).
So hypotenuse H = xSqrt(2), x=H/Sqrt(2).
Using numbers, if H = 7, then x = 7/Sqrt(2) = 7Sqrt(2)/2 to rationalize it.
Remember you can do anything to an equation or inequality as long as ou do it to both sides
also, when multiplying by a negative number in an inequality, don't forget to flip the sign
5+5(x+4)<20
minus 5 from both sides
5(x+4)<15
divide both sides by 5
x+4<3
minus 4 from both sides
x<-1
