bài 1 :
a) (x-45)×29=0
=>x-45=0÷29
=>x-45=0
=>x=0+45
=>x=45
b)21×(34-x)=42
=>34-x=42÷21
=>34-x=2
=>x=34-2
=>x=32
c)156-(x-61)=82
=>x-61=156-82
=>x-61=74
=>x=74+61
=>x=135
bài 2:
a)A={x∈N;3<x<11}
b)B={9;10}
bài 3:
98×31+62=3038+62=3100
Bài `1:`
`(x - 45) . 29 = 0`
`=> x - 45 = 0`
`=> x = 0 + 45`
`=> x = 45`
`21 . (34 - x) = 42`
`=> 34 - x = 42 : 21`
`=> 34 - x = 2`
`=> x = 32`
`156 - (x - 61) = 82`
`=> 156 - x + 61 = 82`
`=> 156 - x = 82 - 61`
`=> 156 - x = 21`
`=> x = 156 - 21`
`=> x = 135`
Bài `2:`
`A = {x ∈ NN** | 4 ≤ x ≤ 10}`
`B = {9 ; 10}`
Bài `3:`
`98 . 31 + 62`
`= 98 . 31 + 31 . 2`
`= (98 + 2) . 31`
`= 100 . 31`
`= 3100`
Đưa thừa số vào trong dấu căn: c) 1/y√19yvới y >0 y d) 1 /3y√27/y2 y với y <0 Rút gọn biểu thức: b) y/2+ 3/4 √1 -4y+ 4y2 với y< 1/2 . Thực hiện phép tính: a)( 2/√3-1 +3/√3-2 +15/3-√3 )*1/√3+5 b,(√14-√7/1-√2 +√15-√5/1-√3)*1/√7 -√5
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Tìm gtln, glnn của $\sqrt[]{1-x}$ $+$ $\sqrt[]{y-x}$
,..............................
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