9 x 111 = 999 To simplify the sum, think of it as making 99. 9 x 11 = 99 Then multiply the answer (99) and 11 by ten. That is your answer
999,999 - 999 * 999/999 = 999,000
The sum 9 + 99 + 999 + 9999 + 99 999 + .... where the last number to be added consists of nine digits of 9 becomes: (10 β 1) + (100 β 1) + (1000 β 1) + (10 000 β 1) + ... where the last multiple of 10 has nine zeros. There are nine pairs of brackets altogether. Add the multiples of 10 first and then subtract 9: The digit 1 appears 9 times in the final answer.
99 x 10 - 99 x 9 = 99(1 x 10 - 1 x 9) = 99(10 - 9) = 99(1) =99
1 x 999, 3 x 333, 9 x 111, 27 x 37
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9 x 111 = 999 To simplify the sum, think of it as making 99. 9 x 11 = 99 Then multiply the answer (99) and 11 by ten. That is your answer
999 x 99 = 98901
999,999 - 999 * 999/999 = 999,000
99 = 2 100 to 999 = 900 x 3 = 2700 1000 to 1999 = 1000 x 4 = 4000 2000 to 2999 = 1000 x 4 = 4000 3000 = 4 10,706
Easier way than what?I presume you mean long multiplication of 999 by 999, adding 998 and adding 1.One way:999 = 1000 - 1 ⇒ 999 x 999 + 998 + 1 = (1000 - 1) x (1000 - 1) + 998 + 1= 10002 - 2 x 1000 + 1 + 998 + 1= 1000000 - 2 x 1000 + 1000= 1000000 - 1000= 999000Another way:998 + 1 = 999 ⇒ 999 x 999 + 998 + 1 = 999 x 999 + 999= 999 x (999 + 1)= 999 x 1000= 999000
The sum 9 + 99 + 999 + 9999 + 99 999 + .... where the last number to be added consists of nine digits of 9 becomes: (10 β 1) + (100 β 1) + (1000 β 1) + (10 000 β 1) + ... where the last multiple of 10 has nine zeros. There are nine pairs of brackets altogether. Add the multiples of 10 first and then subtract 9: The digit 1 appears 9 times in the final answer.
Assuming you mean -2.54545454... x = -2.545454.... x+2 = -0.545454... 100(x+2) = -54.54545454 100(x+2) - (x+2) = 99(x+2) = -54.0000000... x+2 = -54/99 x = -252/99 x = -28/11 or assuming that you mean -2.54254254254... x = -2.54254254... 1000x = -2542.54254... 999x = -2540.00000000... x = -2540/999
x+33=999 x=999-33=966
1 x 999, 3 x 333, 9 x 111, 27 x 37.
999 = 3 x 3 x 3 x 37 or 33 x 37
1 x 99 = 99 2 x 99 = 198 3 x 99 = 297 4 x 99 = 396 5 x 99 = 495 6 x 99 = 594 7 x 99 = 693 8 x 99 = 792 9 x 99 = 891 10 x 99 = 990 11 x 99 = 1089 12 x 99 = 1188