1) 20 - (x + 16) = 5
=> x + 16 = 20 - 5 = 15
=> x = 15 - 16 = -1
Vậy x = -1
2) 14.35.5+10.25.7+20.70
= (14.5).35 + (10.7).25 + 20.70
= 70.35 + 70.25 + 20.70
= 70.(35+25+20)
= 70.80
= 5600
3) 22344 + 44688.82
= 22344 + 22344.2.82
= 22344.(1+164)
= 22344.165
= 3686760
Đúng 100%
1) 20 - ( x + 16 ) = 5
x + 16 = 20 - 5
x + 16 = 15
x = -1
tk mk nha ^_^
1) \(20-\left(x+16\right)=5\)
\(\Leftrightarrow x+16=20-5\)
\(\Leftrightarrow x+16=15\)
\(\Leftrightarrow x=15-16\)
\(\Leftrightarrow x=-1\)
vậy x=-1
2) a) \(14\cdot35\cdot5+10\cdot25\cdot7+20\cdot70\)
\(=\left(14\cdot5\right)\cdot35+\left(10\cdot7\right)\cdot25+20\cdot70\)
\(=70\cdot35+70\cdot25+70\cdot20\)
\(=70\left(35+25+20\right)\)
\(=70\cdot80\)
\(=5600\)
b) \(22344\cdot36+44688\cdot82\)
\(=\left(22344\cdot2\right)\cdot36:2+44688\cdot82\)
\(=44688\cdot18+44688\cdot82\)
\(=44688\left(18+82\right)\)
\(=44688\cdot100\)
\(=4468800\)
1, 20 - ( x + 16 ) = 5
20 - x -16 = 5
- x = 5 - 20 + 16
- x = 1
x = -1
Vậy x = -1
2,
C1 : 22344 . 36 + 44688 . 82 = 22344 . 36 + 22344 . 2 .82
= 22344 . 36 + 22344 . 164
= 22344 . ( 36 + 164 )
= 22344 . 200
= 22344 . 2 . 100
= 44688 . 100
= 4468800
C2 : 22344 . 36 + 44688 . 82 = 22344 . 2 . 18 + 44688 . 82
= 44688 . 18 + 44688 . 82
= 44688 . ( 18 + 82 )
= 44688 . 100
= 4468800
14.35.5+10.25.7+20.70 = 14.5.35+10.7.25+20.70
= 70.35+70.25+20.70
= 70. ( 35+25+20)
= 70. 80
= 5600.
1) 20 - ( x + 16 ) = 5
x + 16 = 20 - 5
x + 16 = 15
x = 15 - 16
x = -1
2) 14.35.5 + 10.25.7 + 20.70
= 7.2.35.5 + 10.25.7 + 20.70
= 7.10.35 + 7.10.25 + 20.70
= 70.35 + 70.25 + 70.20
= 70. ( 35 + 25 + 20 )
= 70. 80
= 5600
22344.36 + 44688.82
= 22344.36 + 22344.2.82
= 22344.36 + 22344.164
= 22344. ( 36 + 164 )
= 22344.200
= 4468800
