-5/23 × 17/26 + 5/-23 × 9/26
5/23 . 17/26 + 9/26 . 5/23
5/23 x 17/26 + 9/26 x 5/23
= 5/23 x(17/26 + 9/26)
= 5/23 x 1
=5/23
Tính hợp lí:
\(\dfrac{-5}{23}\).\(\dfrac{17}{26}\)+\(\dfrac{5}{23}\).\(\dfrac{9}{-26}\)
\(\dfrac{-5}{23}\cdot\dfrac{17}{26}+\dfrac{5}{23}\cdot\dfrac{9}{-29}\)
= \(\dfrac{5}{23}\cdot\dfrac{-17}{26}+\dfrac{5}{23}\cdot\dfrac{-9}{29}\)
= \(\dfrac{5}{23}\left(\dfrac{-17}{26}+\dfrac{-9}{26}\right)\)
= \(\dfrac{5}{23}\cdot\left(-1\right)=\dfrac{-5}{23}\)
\(\dfrac{-5}{23}.\dfrac{17}{26}+\dfrac{5}{23}.\dfrac{9}{-26}=\dfrac{-5}{23}.\left(\dfrac{17}{26}+\dfrac{9}{26}\right)\)
\(=\dfrac{-5}{23}.\left(\dfrac{17+9}{26}\right)=\dfrac{-5}{23}.\dfrac{26}{26}\)
\(=\dfrac{-5}{23}.1=\dfrac{-5}{23}\)
Bài 30: tính giá trị của các bằng cách tính nhanh nhất
a,21/25 x 11/9 x 5/7
b, 5/23 x 17/26 + 5/23 x 9/26
a) Ta có: \(\dfrac{21}{25}\cdot\dfrac{11}{9}\cdot\dfrac{5}{7}\)
\(=\dfrac{21\cdot11\cdot5}{25\cdot9\cdot7}\)
\(=\dfrac{3\cdot7\cdot11\cdot5}{5\cdot5\cdot3\cdot3\cdot7}\)
\(=\dfrac{11}{5\cdot3}=\dfrac{11}{15}\)
a) 21/25. 11/9. 5/7
=(21/25.5/7).11/9
= 3/5. 11/9
=11/15
b) 5/23 . 17/26 . 5/23 . 9/26
=5/23.( 17/26+9/26)
=5/23. 1
=5/23
b) Ta có: \(\dfrac{5}{23}\cdot\dfrac{17}{26}+\dfrac{5}{23}\cdot\dfrac{9}{26}\)
\(=\dfrac{5}{23}\left(\dfrac{17}{26}+\dfrac{9}{26}\right)\)
\(=\dfrac{5}{23}\cdot1=\dfrac{5}{23}\)
Tính
\(\frac{5}{23}\times\frac{17}{26}+\frac{5}{23}\times\frac{9}{26}\)
\(\frac{5}{23}x\left(\frac{17}{26}+\frac{9}{26}\right)\)=\(\frac{5}{23}x\frac{26}{26}\)=\(\frac{5}{23}x1\)=\(\frac{5}{23}\)
\(\frac{5}{23}\)x \(\frac{17}{26}+\frac{5}{23}\)x \(\frac{9}{26}\)
=\(\frac{5}{23}\left(\frac{17}{26}+\frac{9}{26}\right)\)
=\(\frac{5}{23}\)x \(\frac{26}{26}\)
=\(\frac{5}{23}\)x 1
=\(\frac{5}{23}\)
5/23 x 17/26 + 5/23 x 9/26
= 5/23 x ( 17/26 + 9/26)
= 5/23 x 26/26
= 5/23 x 1
= 5/23
dễ quá, chuyện nhỏ như con thỏ gặm cỏ ấy mà
ài 1: Tính giá trị của biểu thức sau:
1)2763 + 152 2)(-7) + (-14)
3)(-35) + (-9) 4)(-5) + (-248)
5)(-23) + 105 6)78 + (-123)
7)23 + (-13) 8)(-23) + 13
9)26 + (-6) 10) (-75) + 50
11)80 + (-220) 12) (-23) + (-13)
13)(-26) + (-6) 14 (-75) + (-50)
15)-18 + (-12) 16)17 + -33
17)(– 20) + -88 18) -3 + 5
19)-37 + 15 20)-37 + (-15)
21)(--32) + 5 22)(--22)+ (-16)
23)(-23) + 13 + ( - 17) + 57 24)14 + 6 + (-9) + (-14)
25) (-123) +-13+ (-7) 26) 0+45+(--455)+-796
câu nầy hơn khó nên mình ko giải đc bạn đợ mình giải đã
1) 2763 + 152 = 2951
2)(-7) + (-14) = -21
3)(-35) + (-9) =-44
4) (-5) + (-248) = -253
Tính nhanh:
5/23 : (3/26+7/9) - 5/23 : (23/26 + 2/9)
Bài 1: Thực hiện các phép tính sau:
1) 21/25 * 11/9 * 5/7
2) 5/23 * 17/26 + 5/23 * 9/26
3) (3/29 - 1/5) * 29/3
4) 12/5 : 16/15
5) 9/88 : 6/5
6) 3/14 : 6/7
Thanks
4.24.5^2-(3^3.18+3^3.12)
31.15.7^2.4-31.49.40
1+2+3+4+5+6+7+8+9+10
1+3+5+7+9+11+13+15+19
2+6+10+14+22+23+26+34
5+8+11+14+17+20+23+26+29
1+6+11+16+21+26+31+36+41+47+51
10+13+16+19+22+25+28+31+34+37+40
5+7+9+11+13+15+17+3+8+13+18+23+28
4+7+10+13+16+19+5+9+13+17+21+25
4.24.52-(33.18+33.12)
=4.24.25-[27.(18+12)]
=(4.25).24-[27.30]
=100.24-810
=2400-810
=1590
4.24.5^2-(3^3.18+3^3.12)
31.15.7^2.4-31.49.40
1+2+3+4+5+6+7+8+9+10
1+3+5+7+9+11+13+15+19
2+6+10+14+22+23+26+34
5+8+11+14+17+20+23+26+29
1+6+11+16+21+26+31+36+41+47+51
10+13+16+19+22+25+28+31+34+37+40
5+7+9+11+13+15+17+3+8+13+18+23+28
4+7+10+13+16+19+5+9+13+17+21+25 = 1590
#HT#
ài 1: Tính giá trị của biểu thức sau:
1)2763 + 152
2)(-7) + (-14)
3)(-35) + (-9)
4)(-5) + (-248)
5)(-23) + 105
6)78 + (-123)
7)23 + (-13)
8)(-23) + 13
9)26 + (-6)
10) (-75) + 50
11)80 + (-220)
12) (-23) + (-13)
13)(-26) + (-6)
14 (-75) + (-50)
15)-18 + (-12)
16)17 + -33
17)(– 20) + -88
18) -3 + 5
19)-37 + 15
20)-37 + (-15)
21)(--32) + 5
22)(--22)+ (-16)
23)(-23) + 13 + ( - 17) + 57
24)14 + 6 + (-9) + (-14)
25) (-123) +-13+ (-7)
26) 0+45+(--455)+-796
1) 2763 +152 =2915
2) (-7) +(-14) = -21
3) (-35) + (-9) = -44
4) (-5) + (-248) = -253
5) (-23) + 105 = 82
6) 78 + (-123) = -45
7) 23 +(-13) = 10
8) (-23) +13 = -10
9) 26 + (-6) = 20
10) (-75) +50 = -25
11) 80 + (-220) = -140
12) (-23) + (-13) = -36
13) (-26) + (-6) = -32
14) (-75) + (-50) = -125
15) ❏-18❏ + (-12) = -17❏ -12
16)17 + ❏ - 33❏ = 17 -32❏
17) (-20) +❏ - 88❏ = -20 -87❏
18) ❏- 3❏+ ❏5❏ = ❏5❏ -2❏
19)❏-37❏+❏15❏ = ❏15❏ -36❏
20) ❏-37❏+(-❏15❏) = -❏15❏ - 36❏
21) (-❏-32❏) +❏5❏ = ❏5❏ -33❏
22) (-❏-22❏) + (-❏16❏) = -❏16❏ -23❏
23) (-23) +13 +(-17) +57 = 30
24) 14 +6 + (-9) + (-14) = -3
25) (-123 ) +❏-13❏+(-7) = -130-12❏
26) ❏0❏ + ❏45❏ +(-❏-455)❏+❏-796❏ = ❏45❏-❏\(^2\) -1250❏