\(a,\dfrac{3}{5}+\dfrac{-5}{9}\)
\(b,\dfrac{1}{3}+\dfrac{-4}{3};\dfrac{4}{7}\)
\(c,-\dfrac{27}{23}+\dfrac{5}{21}+\dfrac{4}{23}+\dfrac{16}{21}+\dfrac{1}{2}\)
\(d,\dfrac{-8}{9}+\dfrac{1}{9}.\dfrac{2}{9}+\dfrac{1}{9}.\dfrac{7}{9}\)
1\(\dfrac{4}{23}\) +\(\dfrac{5}{21}\) - \(\dfrac{4}{23}\) + 0,5 +\(\dfrac{16}{21}\)
\(\dfrac{29-x}{21}\)+\(\dfrac{27-x}{23}\)+\(\dfrac{25-x}{25}\)+\(\dfrac{23-x}{27}\)+\(\dfrac{21-x}{29}\)=\(\dfrac{(29-x+1}{21}\)+\(\dfrac{(27-x+1)}{23}\)+\(\dfrac{(25-x+1)}{25}\)+\(\dfrac{(23-x+1)}{21}\)=-5 +5
GIẢI nốt hộ mình với ạ
a) 21/47 + 9/45 +26/47 + 4/5
= (21/47 + 26/47) + (9/45 + 4/5)
=1+1 = 2
b) 15/12 + 5/13 - 3/12 - 18/13
= (15/12 - 3/12) + (18/13 - 5/13)
=1+1 = 2
c) 13/25 + 6/41 - 38/25 + 35/41 - 1/2
= (38/25 - 13/25) + (35/41 + 6/41) + 1/2
= 1+1 + 1/2 = 5/2
d) 27/23 + 5/21 - 4/23 + 6/21 + 1/2
= (27/23 - 4/23) + (6/21 - 5/21) + 1/2
= ..........................
Đúng không? Phần sau mình tính sao ra kết quả lạ lắm, tính giúp mình.
a) 1 và 4/23+(5/21-4/23)+16/21-1/2 b)75%-(5/2+5/3)+(-1/2) ngũ3 c)-3/4.(-55/9).8/11 d)-3/8.6/13+7/13.-3/8+ 1 và 3/8
1/8 + 2/5 - 4/32
-1/15 + 23/27 + -14/15 + 31/27
3/7 . 22/21 + 3/7 . 5/21 + 15/21 . 3/7
-8/9 : 2/3 +1/9 : -2/3
15*37*4+120*21+21*5*12
15*(27+18+6)+15*(23+12)
10*(81+19)+100+50*(91+9)
42*(15+96)+6*(25+4)*7
16*(27+75)+8*(53+25)*2
Bài 1: Tính hợp lí nhất
1, 2155– (174 + 2155) + (-68 + 174)
2, -25 . 72 + 25 . 21 – 49 . 25
3, 35(14 –23) – 23(14–35)
4, 8154– (674 + 8154) + (–98 + 674) 5, – 25 . 21 + 25 . 72 + 49 . 25
6, 27(13 – 16) – 16(13 – 27)
7, –1911 – (1234 – 1911)
8, 156.72 + 28.156
9, 32.( -39) + 16.( –22)
10, –1945 – ( 567– 1945)
11, 184.33 + 67.184
12, 44.( –36) + 22.( –28)