34.(66-5)-66.(34+5)
34 . ( 66 - 5 ) - 66 . ( 34+5 ) . Tính hợp lí
Ta có 34.(66 - 5) - 66.(34 + 5)
= 34.66 - 34.5 - 66.34 - 66.5
= -5.(34 + 66)
= - 5.100 = - 500
Tính bằng cách hợp lí nhất:
34.(66-5) -66.(34+5)
34(66-5)-66(34+5)=34.66-34.5-34.66-66.5=(34.66-34.66)-5(34+66)=-500
Tính hợp lý:
34.(66-5)-66.(34+5)
=34x66-34x5 -66x34-66x5
=-34x5-66x5
=5x(-34-66)=5x(-100)=-500
34.(66-5)-66.(34+5)=(34-34).(66-66).(5+5)=0.0.10=0
\(34.\left(66-5\right)-66.\left(34+5\right)\)
\(=34.66-34.5-66.34-66.5\)
\(=\left(34.66-66.34\right)-\left(34.5+66.5\right)\)
\(=0-\left(34+66\right).5\)
\(=0-100.5\)
\(=0-500\)
\(=-500\)
Tính hợp lí
1. 453 . (-27) . 27 . 253
2. 34. ( 66 - 5 ) . 66 . ( 34 + 5 )
tính nhanh
34.(66-5)-66.(34+5)
trình bày cả nha
cám ơn trc
\(34.\left(66-5\right)\)\(-66.\left(34+5\right)\)
\(=34.66-34.5\)\(-66.34-66.5\)
\(=-34.5-66.5\)
\(=5.\left(-34-66\right)\)
\(=5.\left(-100\right)\)
\(=-500\)
k mk nhe
Tính:
. . . .ai chỉ e cách làm nhanh v
34.66 - 34.4 - 66.34 - 66.4
= ( 34.66 - 66.34) - ( 34.4 +66.4)
= 0 - 4.(34+66)
= -4.100
= -400
\(34.\left(66-4\right)-66.\left(34+4\right)\\ =34.66-34.4-66.34-66.4\\ =\left(34-34-4\right).66-34.4\\ =-4.66-34.4\\ =4.\left(-66\right)-34.4\\ =4.\left(-66-34\right)\\ =4.\left(-100\right)\\=-400\\ -264.\left(-400\right).264.40\\ =264.400.264.40\\ =264.4.100.264.4.10\\ =264.4.264.4.\left(100.10\right)\\ =\left(264.4\right)^2.1000\\ =1115136.1000=1115136000\)
34+2.(x-5)mũ 2=66
`34+2(x-5)^2=66`
`=>2(x-5)^2=66-34`
`=>2(x-5)^2=32`
`=>(x-5)^2=32:2`
`=>(x-5)^2=16=(4)^2=(-4)^2`
`=>` $\left[ \begin{array}{l}x-5=4\\x-5=-4\end{array} \right.$
`=>` $\left[ \begin{array}{l}x=9\\x=1\end{array} \right.$
Vậy x=9 hoặc x=1
Ta có: \(34+2\left(x-5\right)^2=66\)
\(\Leftrightarrow2\left(x-5\right)^2=32\)
\(\Leftrightarrow\left(x-5\right)^2=16\)
\(\Leftrightarrow\left[{}\begin{matrix}x-5=4\\x-5=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=9\\x=1\end{matrix}\right.\)
Vậy: \(x\in\left\{1;9\right\}\)
66+34+34+66
k mk k lai
\(66+34+34+66\)
\(=\left(66+34\right)+\left(34+66\right)\)
\(=100+100\)
\(=100.2\)
\(=200\)
Tính giá trị của biểu thức
a) 27 + 34 + 66 b) 7 x 5 x 2
a) 27 + 34 + 66 = 27 + (34 + 66) = 27 + 100 = 127 | b) 7 x 5 x 2 = 7 x (5 x 2) = 7 x 10 = 70 |