(54+47).(89-27).(24-42)
(169-42).(169-52)......(169-132)
Rút gọn các phân số sau: a) \(\dfrac{-21}{28}\); \(\dfrac{-39}{52}\); \(\dfrac{-24}{63}\); \(\dfrac{12}{-21}\) b, \(\dfrac{-270}{450}\); \(\dfrac{11}{-143}\); \(\dfrac{-132}{156}\); \(\dfrac{-26}{169}\)
g) (15 + 37) + (52 – 37 – 17) h) (38 – 42 +14) - (38 – 42 - 15) i) (27 + 65 ) + (346 - 27- 65) k) - (27 + 65) - (346 – 27 - 65) l) (42 – 69 + 17) - (42 + 17) m) 24. (16 - 5) – 16. (24 – 5 ) n) (-12). 47 – 12 . 52 + (-12) p) 51 . (69 - 25) – 69. (51 - 25) |
g) (15 + 37) + (52 – 37 – 17) = 15 + 37 + 52 – 37 – 17 = 15 + 52 – 17 = 50 h) (38 – 42 +14) - (38 – 42 - 15) = 38 – 42 +14 - 38 + 42 + 15 = 14 + 15 = 29 i) (27 + 65 ) + (346 - 27- 65) = 27 + 65 + 346 - 27- 65 = 346 k) - (27 + 65) - (346 – 27 - 65) = -27 - 65 - 346 + 27 + 65 = -346 l) (42 – 69 + 17) - (42 + 17) = 42 – 69 + 17 - 42 - 17 = – 69 m) 24. (16 - 5) – 16. (24 – 5 ) = 24. 16 - 24 . 5 - 16 . 24 + 16. 5 = - 24 . 5 + 16. 5 = -8 . 5 = -40 n) (-12). 47 – 12 . 52 + (-12) = -12 (47 - 52 + 1) = -12 . (-4) = 48 p) 51 . (69 - 25) – 69. (51 - 25) = 51 . 69 - 51 . 25 – 69. 51 + 69. 25 = - 51 . 25 + 69. 25 = (- 51+ 69).25 = 450 |
a/ (-169) + 72.(-169) + (-169).27
\(\left(-169\right)+72\left(-169\right)+\left(-169\right).27\)
\(=\left(-169\right).\left(1+72+27\right)\)
\(=\left(-169\right).100\)
\(=-16900\)
a/ (-169) + 72.(-169) + (-169).27
= (-169).1+72.(-169)+(-169).27
=(-169).(1+72+27)
=(-169).100
= -16900
a) 2×24×25+3×41×16+6×2×8×17
b)15×360+15×2×27+1500
c)47×63+53×21+47×37+53
d)2×169×12-3×68×8-24
e)2×56×24-3×36×16+4×12×95-6×3×8×5
f)(36×15×169)÷(5×18×13)
h)(112+2×28-5×28)÷28
i)1448-(448+500)
rut gon roi tinh: (84/144-225/60-169/65):(3/2-64/48-96/42)
84/144 = 7/12 225/60 = 15/4 169/65 = 13/5
64/48 = 4/3 96/42 = 16/7
( 7/12 - 15/4 - 13/5 ) : ( 3/2 - 4/3 - 16/7 )
= -173/30 : -89/42
= 1221/445
84/144 = 7/12;225/60 = 15/4;169/65 = 13/5;64/48 = 4/3;96/42 = 16/7
( 7/12 - 15/4 - 13/5 ) : ( 3/2 - 4/3 - 16/7 )
= -173/30 : -89/42
= 1221/445
Tính hợp lí:
1) -(-66)+34+(-73)-27+99
2) 54-(45-30+54)-30+5
3)42-56+33-(33+56+42)
4)50-(47+50-18)+(47-18)
5)|25-24-10|-(28-30+4)
1; - (-66) + 34 + (-73) - 27 + 99
= 66 + 34 - 73 - 27 + 99
= (66 + 34) - (73 + 27) + 99
= 100 - 100 + 99
= 0 + 99
= 99
2; 54 - (45 - 30 + 54) - 30 + 5
= 54 - 45 + 30 - 54 - 30 + 5
= (54 - 54) + (30 - 30) - (45 - 5)
= 0 + 0 - 40
= - 40
3; 42 - 56 + 33 - (33 + 56 + 42)
= 42 - 56 + 33 - 33 - 56 - 42
= (42 - 42) - (33 - 33) - (56 + 56)
= 0 - 0 - 112
= - 112
Tính
E=(169-4^2).(169-5^2).(169-6^2).(169-7^2).(169-8^2).(169-9^20).(169-10^2).(169-11^2).(169-12^2).(169-13^2)
rút gọn phân số là
45 / 27 25 / 50 12 / 21 24 / 56
22 / 121 196 / 28 26 / 169 221 / 187
45/27=5/3
25/50=1/2
12/21=4/7
24/56=3/7
22/121=2/11
196/28=7
26/169=2/13
221/187=13/11
Tìm X :
1) ( 2016 + X ) : 169 = X
2) 51 + ( 26 - 3X ) : 5 = 55
3) [ ( X + 32 ) - 17 ] . 2 = 42
1) 2016 +x = 169x
<=> 2016 = 168x
<=> x=12
2) (26 - 3x) : 5= 4
<=> 26 - 3x = 20
<=> 3x =6
<=> x=2
3) x + 32 - 17 = 21
<=> x + 15 = 21
<=> x= 6
Đặt tính rồi tính:
169 + 729 137 +208
489 – 176 905 - 89