x-(81-91-199-111+220)+123-111
(a) S = −11 − 12 − 13 + 91 + 92 + 93
(b) S = −111 + 223 − (123 − 111)
(c) S = (127 − 263) − (27 − 153)
(d) S = (−2)4.289 − 16.189
(e) S = −56.43 + (−56).25 − 56.32
(f) S = −2.(77 − 20) + 77(2 − 20)
(g) S = −11(200 + 31) − 31(−11 − 100)
a)\(S=\left(-11+91\right)+\left(92-12\right)+\left(93-13\right)\\ S=80+80+80=240\)
\(\)b)\(S=-111+223-123+111\\ S=\left(-111+111\right)+\left(223-123\right)\\ S=0+100=100\)
c)\(S=127-263-27+153\\ S=\left(127-27\right)-\left(263-153\right)\\ S=100-110=-10\)
12 - 3 = ? + 91 = ? + 10 + 1 = ?
123 - 2 + 111 =
=
12 ? 3 = 4 x 4 = ? + 45 = ?
12 - 3 = ?
12 - 3 = 9 + 91 = 100 + 10 + 1 = 111
123 - 2 + 111 = 121 + 111
= 232
12 : 3 = 4 x 4 = 16 + 45 = 61
12 - 3 = 9
12 - 3 = 9 + 91 = 100 + 10 + 1 = 111
123 - 2 + 111 = 121 + 111
= 232
12 : 3 = 4 x 4 = 16 + 45 = 61
12 - 3 = 9
123 + 111
234 + 222
111 + 0
11167 x 0
123 + 111 = 234
123 + 222 =345
111 + 0 =111
11167 x 0 = 0
123 + 111 = 234
234 + 222 = 456
111 + 0 = 111
11167 x 0 = 0
123+ 111= 234
234+222 = 456
111+0=111
11167 x 0= 0
70-8+123+234-111+789-222-111=?
Tìm X :
A.) X - 123 = 123 x 8
B.) X + 123 : 2 = 111 x 9
a) x-123=984
x=984+123
x=1107
b) x+123:2=999
x=999-(123:2)
x=937,5
CMR :111...111 ( 81 CHỮ SỐ 1 ) CHIA HẾT CHO 81
111\37<x<91\13
Ta có : 111/37 < x < 91/13
Suy ra 3 < x < 7
Nên x = 4 ; 5 ; 6
1) Tính nhanh :
a) 8 x 17 x 125
c) 4 x 37 x 25
d) 43 x 27 + 93 x 43 + 57 x 81 + 69 x 57
e) 123456789 x 45 biết 12345679 x 9 = 111 111 111
7 x 17 x 125 = (8 x 125) x 17 = 1000 x 17 = 17000
4 x 37 x 25 = (25 x 4 ) x 7 = 100 x 7 = 700
43 x 27 + 93 x 43 + 57 x 81 + 69 x 57 = 43 x (27 + 93) + 57 x (81 +69) = 43 x 120 + 57 x 120 + 57x30 = 120 x (43 + 57) + 1710 = 12000 + 1710 = 13710
\(A=\frac{\frac{4}{111}+\frac{4}{123}-\frac{4}{999}}{\frac{2}{111}+\frac{2}{123}-\frac{2}{999}}\)
\(A=\frac{\frac{4}{111}+\frac{4}{123}-\frac{4}{999}}{\frac{2}{111}+\frac{2}{123}+\frac{2}{999}}\)
\(=\frac{4.\left(\frac{1}{111}+\frac{1}{123}+\frac{1}{999}\right)}{2.\left(\frac{1}{111}+\frac{1}{123}+\frac{1}{999}\right)}\)
\(=\frac{4}{2}=2\)