xin ctl đúng ạ
120:{[15.(15-8)+(-5)]}
6. Điền dấu >; <; = vào chỗ chấm:
\(\dfrac{5}{15}\) ...............\(\dfrac{12}{8}\)
\(\dfrac{5}{15}\) ............... \(\dfrac{3}{9}\)
\(\dfrac{5}{15}\) ................ \(\dfrac{5}{8}\)
Giúp mình nhanh với ạ, làm đúng mình tick cho ạ
xin ctl ạaa
92+(-13).36+(-13).34
gấp ạ
92+(-13).36+(-13).34
=92+(-13).(36+34)
=92+(-13).70
=92+(-910)
=-818
92+(-13).36+(-13).34
=92+(-13).(36+34)
=92+(-13).70
=92+(-910)
=-818
ah chụy oiw cho iem xin phép hỏi lại câu này ạ :
8/15 :2/11 - 7/15 : 2/11
\(\dfrac{8}{15}:\dfrac{2}{11}-\dfrac{7}{15}:\dfrac{2}{11}=\left(\dfrac{8}{15}-\dfrac{7}{15}\right):\dfrac{2}{11}=\dfrac{1}{15}:\dfrac{2}{11}=\dfrac{11}{30}\)
\(\left(\dfrac{8}{15}-\dfrac{7}{15}\right):\dfrac{2}{11}=\dfrac{1}{15}\)x\(\dfrac{11}{2}=\dfrac{11}{30}\)
\(\dfrac{8}{15}\) : \(\dfrac{2}{11}\) - \(\dfrac{7}{15}:\dfrac{2}{11}\) = \(\dfrac{11}{30}\)
giúp mình bài này nha
-16:(-8)+5[3-15:5+2(-3+4)]
15*(-236)+15*235
237*(-28)+28*137
(-3)*(-17)+3*(120-17)
(-8)*72+8*(-19)-(-8)
`#3107.101107`
\(-16 \div (-8)+5[3-15\div5+2(-3+4)]\)
`= 2 + 5(3 - 3 - 6 + 8)`
`= 2 + 5*(-6 + 8)`
`= 2 + 5*2`
`= 2(5 + 1)`
`= 2*6 = 12`
____
`15*(-236)+15*235`
`= 15 * (-236 + 235)`
`= 15 * (-1)`
`= -15`
____
`237*(-28)+28*137`
`= 28 * (-237 + 137)`
`= 28 * (-100)`
`= -2800`
____
`(-3)*(-17)+3*(120-17)`
`= 3 * 17 + 3 * (120 - 17)`
`= 3 * (17 + 120 - 17)`
`= 3 * 120`
`= 360`
____
`(-8)*72+8*(-19)-(-8)`
`= 8 * (-72) + 8 * (-19) + 8`
`= 8 * (-72 - 19 + 1)`
`= 8 * (-90)`
`= -720`
a)−16÷(−8)+5[3−15÷5+2(−3+4)]
=2+5(3−3−6+8)
=2+5⋅(−6+8)
=2+5⋅2
=2(5+1)
=2⋅6
=12
b)15⋅(−236)+15⋅235
=15⋅(−236+235)
=15⋅(−1)
=−15
c)237⋅(−28)+28⋅137
=28⋅(−237+137)
=28⋅(−100)
=−2800
d)(−3)⋅(−17)+3⋅(120−17)
=3⋅17+3⋅(120−17)
=3⋅(17+120−17)
=3⋅120
=360
e)(−8)⋅72+8⋅(−19)−(−8)
=8⋅(−72)+8⋅(−19)+8
=8⋅(−72−19+1)
=8⋅(−90)
=−720
Bài 2: Tìm x:
a) 128 – 2x = -8 – x
b) x – (-15).2 = 55 – 7.(-3)
c) 66 – [5 – (-x)] = 169
d) (8 – 2x).(8 + x) = 0
e) 7 – [x2 + (-9)] = -20
mn ơi giúp mình
đang gấp ạ
xin cảm ơn
Rút gọn
\(\sqrt{8-2\sqrt{15}}+\sqrt{48+6\sqrt{15}}\)
\(\sqrt{8-\sqrt{60}}-\sqrt{23-\sqrt{240}}\)
\(\sqrt{29-12\sqrt{5}}-\sqrt{24+8\sqrt{5}}\)
Mọi người giúp mình với ạ. Mình xin chân thành cảm ơn!
\(\sqrt{8-2\sqrt{15}}+\sqrt{48+6\sqrt{15}}\\ =\sqrt{5-2\cdot\sqrt{5}\cdot\sqrt{3}+3}+\sqrt{45+2\cdot3\sqrt{5}\cdot\sqrt{3}+3}\\ =\sqrt{\left(\sqrt{5}\right)^2-2\cdot\sqrt{5}\cdot\sqrt{3}+\left(\sqrt{3}\right)^2}+\sqrt{\left(3\sqrt{5}\right)^2+2\cdot3\sqrt{5}\cdot\sqrt{3}+\left(\sqrt{3}\right)^2}\\ =\sqrt{\left(\sqrt{5}-\sqrt{3}\right)^2}+\sqrt{\left(3\sqrt{5}+\sqrt{3}\right)^2}\\ =\sqrt{5}-\sqrt{3}+3\sqrt{5}+\sqrt{3}=4\sqrt{5}\)
\(\sqrt{8-\sqrt{60}}-\sqrt{23-\sqrt{240}}\\ =\sqrt{8-\sqrt{4\cdot15}}-\sqrt{23-\sqrt{4\cdot60}}\\ =\sqrt{8-2\sqrt{15}}-\sqrt{23-2\sqrt{60}}\\ =\sqrt{\left(\sqrt{5}-\sqrt{3}\right)^2}-\sqrt{20-2\cdot\sqrt{20}\cdot\sqrt{3}+3}\\ =\sqrt{5}-\sqrt{3}-\sqrt{\left(\sqrt{20}-\sqrt{3}\right)^2}\\ =\sqrt{5}-\sqrt{3}-\sqrt{20}+\sqrt{3}\\ =\sqrt{5}-2\sqrt{5}=-\sqrt{5}\)
a) 7/15 + (- 4/11) + 8/15 - 2, 5 + 7/15 ( giúp mik với ạ )
\(\dfrac{7}{15}+\left(\dfrac{-4}{11}\right)+\dfrac{8}{15}-2,5+\dfrac{7}{15}\)
\(=\dfrac{7}{15}+\left(\dfrac{-4}{11}\right)+\dfrac{8}{15}+\left(\dfrac{-5}{2}\right)+\dfrac{7}{15}\)
\(=\left(\dfrac{7}{15}+\dfrac{8}{15}+\dfrac{7}{15}\right)+\left[\left(\dfrac{-4}{11}\right)+\left(\dfrac{-5}{2}\right)\right]\)
\(=\dfrac{22}{15}+\left(\dfrac{-63}{22}\right)\)
\(=\dfrac{-461}{330}\)
\(=\dfrac{7}{15}+\dfrac{8}{15}+\dfrac{-4}{11}-\dfrac{5}{2}+\dfrac{7}{15}=\dfrac{22}{15}-\dfrac{63}{22}=-\dfrac{461}{330}\)
=7/15+8/15+(−4)/11−5/2+7/15=(22/15−63/22)=(−461)/330
x/2008 - 1/10 -1/15-...-1/120= 5/8
các bn giúp mk nhamk đng cần gấp lắm
Tinh nhanh
a) 2 + 4 + 6 + 8 + ... + 120
b) 15 + 20 + 25 + ... + 400
nhanh nhanh giùm mình ạ