2+3=8
3+7=27
4+5=32
5+8=60
6+7=72
7+8=??
4) 87+(-45)-(-79)
5) (-15)+45-62
6) 120: (-5)+72
7) -147-130: (-13)
8) 125. (-8) : (-25). (-7)
9) 25-18+(-43)
10) -18-3.(-20)
4) 121
5) - 32
6) 48
7) - 137
8) - 280
9) - 36
10) 42
4) 41
5) -32
6) 48
7) -137
8) -280
9) -36
10) 42
bài 1: tìm số tự nhiên x, biết:
a)83-6.(x-7)=35
b)246+7.(x+15)=442
c)303:{606:[450-(x.43-83.2)]}=101
d)(196-23.x).32025=32029
giúp mình làm với, mình cần gấp, cảm ơn, ai nhanh nhất mình sẽ tick!!!!
a)83-6.(x-7)=35
6(x-7)=83-35=48
x-7=48:6=8
x=8+7=15
b)246+7.(x+15)=442
7(x+15)=442-246=196
x+15=196:7=28
x=28-15=13
c)303:{606:[450-(x.43-83.2)]}=101
606:[450-(x.43-83.2)]=303:101=3
450-(x.43-83.2)=606:3=202
x . 64-512=450-202=248
x . 64=248+512=760
x=760:64=11,875
22/25 x 5/11 - 33/25 : 11/5 + 58/11
8 3/11 - (3 5/7 - 7 8/11 )
1/5 + 7/5 : x = -3/20
5/6x + 325% = 3/2x -30,75
\(\frac{22}{25}\times\frac{5}{11}-\frac{33}{25}:\frac{11}{5}+\frac{58}{11}\)
\(=\frac{22}{25}\times\frac{5}{11}-\frac{33}{25}\times\frac{5}{11}+\frac{58}{11}\)
\(=\frac{5}{11}\times\left(\frac{22}{25}+\frac{33}{25}\right)+\frac{58}{11}\)
\(=\frac{5}{11}\times\frac{11}{5}+\frac{58}{11}\)
\(=1+\frac{58}{11}\)
\(=\frac{11}{11}+\frac{58}{11}\)
\(=\frac{69}{11}\)
\(8\frac{3}{11}-\left(3\frac{5}{7}-7\frac{8}{11}\right)\)
\(=\frac{91}{11}-\left(\frac{26}{7}-\frac{85}{11}\right)\)
\(=\frac{91}{11}-\frac{26}{7}+\frac{85}{11}\)
\(=\frac{91}{11}+\frac{85}{11}-\frac{26}{7}\)
\(=16-\frac{26}{7}\)
\(=\frac{86}{7}\)
\(\frac{5}{6}x+325\%=\frac{3}{2}x-30,75\)
\(=>\frac{5}{6}x+3,25=\frac{3}{2}x-30,75\)
\(=>\frac{5}{6}x-\frac{3}{2}x=-30,75-3,25\)
\(=>\frac{-2}{3}x=-34\)
\(=>x=-34:\left(-\frac{2}{3}\right)\)
\(=>x=-34.\left(\frac{3}{-2}\right)\)
\(=>x=51\)
Giải giúp mình:
1/ 1/5 + -1/-4
2/ 3/4 + -7/8
3/ 11/18 + 7/-9
4/ 2/-15 + 3/7 + -4/-30
5/ 8/-17 + (-2)
1: =1/5-1/4=-1/20
2: =6/8-7/8=-1/8
3: =11/18-14/18=-3/18=-1/6
4: =-28/210+90/210+28/210=3/7
5: =-8/17-34/17=-42/17
1)\(\dfrac{1}{5}+\dfrac{-1}{-4}=\dfrac{4}{20}+\dfrac{5}{20}=\dfrac{9}{20}\)
\(\)2)\(\dfrac{3}{4}+\dfrac{-7}{8}=\dfrac{6}{8}+\dfrac{-7}{8}=\dfrac{-1}{8}\)
3)\(\dfrac{11}{18}+\dfrac{-7}{9}=\dfrac{11}{18}+\dfrac{-14}{18}=\dfrac{-3}{18}=\dfrac{-1}{6}\)
4)\(\dfrac{2}{-15}+\dfrac{3}{7}+\dfrac{-4}{-30}=\dfrac{-2}{15}+\dfrac{2}{15}+\dfrac{3}{7}=0+\dfrac{3}{7}=\dfrac{3}{7}\)
5)\(\dfrac{8}{-17}+\left(-2\right)=\dfrac{-8}{17}+\dfrac{-34}{17}=\dfrac{-42}{17}\)
Số bị chia | 425 | 425 | 727 | 727 |
Số chia | 6 | 7 | 8 | 9 |
Thương | ||||
Dư |
Số bị chia | 425 | 425 | 727 | 727 |
Số chia | 6 | 7 | 8 | 9 |
Thương | 70 | 60 | 90 | 80 |
Dư | 5 | 5 | 7 | 7 |
1.Tính nhanh nếu có thể:
1) (+15)+(+17)
2) (-3)+(-7)
3) (-25)+(+4)
4) (-6)+(-54)
5) (-15)+20
6)(-5)+8+7+5
7) (-8)+(-11)+(-2)
8) 15+(-5)+(-14)+(-16)
9) (-20)+(-14)+3+(-86)
10)(-136)+123+(-264)+(-83)+240
11) (-596)+2001+1999+(-404+189)
12, ( 314 + ( -153) +64 +121+(-247)+218
1) \(\left(+15\right)+\left(+17\right)=15+17=32\)
2) \(\left(-3\right)+\left(-7\right)=-3-7=-\left(3+7\right)=-10\)
3) \(\left(-25\right)+\left(+4\right)=-25+4=-\left(25-4\right)=-21\)
4) \(\left(-6\right)+\left(-54\right)=-6-54=-\left(6+54\right)=-60\)
5) \(\left(-15\right)+20=20-15=5\)
6) \(\left(-5\right)+8+7+5\)
\(=\left(-5+5\right)+\left(8+7\right)\)
\(=15\)
7) \(\left(-8\right)+\left(-11\right)+\left(-2\right)\)
\(=\left[\left(-8\right)+\left(-2\right)\right]+\left(-11\right)\)
\(=\left(-10\right)+\left(-11\right)\)
\(=-21\)
8) \(15+\left(-5\right)+\left(-14\right)+\left(-16\right)\)
\(=\left[15+\left(-5\right)\right]+\left[\left(-14\right)+\left(-16\right)\right]\)
\(=10+\left(-30\right)\)
\(=-20\)
9) \(\left(-20\right)+\left(-14\right)+3+\left(-86\right)\)
\(=\left[\left(-20\right)+3\right]+\left[\left(-14\right)+\left(-86\right)\right]\)
\(=\left(-17\right)+\left(-100\right)\)
\(=-117\)
10) \(\left(-136\right)+123+\left(-264\right)+\left(-83\right)+240\)
\(=\left[\left(-136\right)+\left(-264\right)\right]+\left[123+\left(-83\right)\right]+240\)
\(=\left(-400\right)+40+240\)
\(=\left(-360\right)+240\)
\(=-120\)
11) \(\left(-596\right)+2001+1999+\left(-404+189\right)\)
\(=\left(-596\right)+2001+1999-404+189\)
\(=\left[\left(-596\right)-404\right]+\left(2001+189\right)+1999\)
\(=\left(-1000\right)+2190+1999\)
\(=1190+1999\)
\(=3189\)
12) \(314+\left(-153\right)+64+121+\left(-247\right)+218\)
\(=\left(314+64+121\right)+\left[\left(-153\right)+\left(-247\right)\right]+218\)
\(=\left(378+121\right)+\left(-400\right)+218\)
\(=499-400+218\)
\(=99+218\)
\(=317\)
\(\text{#}Toru\)
4) 87+(-45)-(-79)
5) (-15)+45-62
6) 120: (-5)+72
7) -147-130: (-13)
8) 125. (-8) : (-25). (-7)
9) 25-18+(-43)
10) -18-3.(-20)
Mấy bạn ghi cách viết ra giúp mình . Cảm ơn
4) 87+(-45)-(-79)= 87 + ( -45 ) + 79 = 121
5) (-15)+45-62= 30 - 62 = -32
6) 120: (-5)+72= -24 + 72 = 48
7) -147-130: (-13)= -147 - ( -10 ) = -137
8) 125. (-8) : (-25). (-7)= -1000 : (-25) (-7)= -280
9) 25-18+(-43) = 7 + ( -43) = -36
10) -18-3.(-20)= -18-( -60) = 42
Tính bằng cách thuận tiện nhất:
5 3/4 : 3 + 2 1/4 x 1/3 - 1/8
3/5 : 5/6 : 6/7 : 7/8 + 2/5 + 23/35
\(5\dfrac{3}{4}:3+2\dfrac{1}{4}\times\dfrac{1}{3}-\dfrac{1}{8}=\left(5\dfrac{3}{4}+2\dfrac{1}{4}\right)\times\dfrac{1}{3}-\dfrac{1}{8}\\ =8\times\dfrac{1}{3}-\dfrac{1}{8}=\dfrac{8}{3}-\dfrac{1}{8}=\dfrac{61}{24}\\ ----\\ \dfrac{3}{5}:\dfrac{5}{6}:\dfrac{6}{7}:\dfrac{7}{8}+\dfrac{2}{5}+\dfrac{23}{35}\\ =\dfrac{3}{5}\times\dfrac{6}{5}\times\dfrac{7}{6}\times\dfrac{8}{7}+\dfrac{2}{5}+\dfrac{23}{35}=\dfrac{18}{25}\times\dfrac{4}{3}+\dfrac{2}{5}+\dfrac{23}{35}=\dfrac{353}{175}\)
So sánh:
a.2 ngũ 48 và 8 ngũ 17
B, 35.6 ngũ 3 và 7 ngũ 5
C,25 ngũ 5 và 125 và 3
D,303 ngũ 606 và 606 ngũ 303
Nhanh m tick cho 5 bạn nhanh nhất nhé!!!!
2^48 = (2^3)^16 = 8^16
8^16 < 8^17
Vậy 2^48 < 8^17
35.6^3 = 7.5.6^3
7^5 = 7.7.7^3
7.5.6^3 < 7.7.7^3
Vậy 35.6^3 < 7^5
25^5 = (5^2)^5 = 5^10
125^3 = (5^3)^3 = 5^9
5^10 > 5^9
Vậy 25^5 > 125^3