6,35 x X + 1,25 x X + 2,4 x X = 20
X x (6,35 + 1,25 + 2,4) = 20
X x 10 = 20
x = 2
6,35 x X + 1,25 x X + 2,4 x X = 20
X x (6,35 + 1,25 + 2,4) = 20
X x 10 = 20
x = 2
Tính giá trị biểu thức:
a) 3,54 x 73 + 0,23 x 25 + 3,54 x 27 + 0,17 x 25
b) 12,25 : ( \(5\frac{9}{20}\) - \(4\frac{1}{5}\) ) + 2,4 x 3
tính nhanh :
14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
\(\frac{1\text{x}3\text{x}5+2\text{x}6\text{x}10+4\text{x}12\text{x}20+7\text{x}21\text{x}35}{1\text{x}5\text{x}7+2\text{x}10\text{x}14+4\text{x}20\text{x}28+7\text{x}35\text{x}49}\)
( hơi nhỏ xíu )
101 x 9,4 - 9,4 + 25 x 2,4/ 250% x 125% x 32
2,4 x 45,6 + 0,12 x 53,1 x 20 + 3 x 1,3 x 0,8 =
Bài 1 :
S1= 1/6 + 1/12 + 1/20 + 1/42 + ...........+ 1/90 + 1/110
S2 = 1/2.15 + 1/15.3 + 1/3.21 + ............+ 6/87.90
Bài 2:
1) x . 5 + x : 100 = 25,-5
2) ( x-7 ) . ( 4x -8 ) = 0
3) 1/1/35 : (1/5 – 1/7 ) – 3/ 3x-2 = 1/1/14: ( 1/2 -1/7)
4 )1/1/3 + 1/6 + 1/10 + ……. + 2/ x.(x+1) = 16/9
Bài 1 :
S1= 1/6 + 1/12 + 1/20 + 1/42 + ...........+ 1/90 + 110
S2 = 1/2.15 + 1/15.3 + 1/3.21 + ............+ 6/87.90
Bài 2:
1) x . 5 + x : 100 = 25,-5
2) ( x-7 ) . ( 4x -8 ) = 0
3) 1/1/35 : (1/5 – 1/7 ) – 3/ 3x-2 = 1/1/14: ( 1/2 -1/7)
4 )1/1/3 + 1/6 + 1/10 + ……. + 2/ x.(x+1) = 16/9
Bài 1 :
S1= 1/6 + 1/12 + 1/20 + 1/42 + ...........+ 1/90 + 110
S2 = 1/2.15 + 1/15.3 + 1/3.21 + ............+ 6/87.90
Bài 2:
1) x . 5 + x : 100 = 25,-5
2) ( x-7 ) . ( 4x -8 ) = 0
3) 1/1/35 : (1/5 – 1/7 ) – 3/ 3x-2 = 1/1/14: ( 1/2 -1/7)
4 )1/1/3 + 1/6 + 1/10 + ……. + 2/ x.(x+1) = 16/9
b , 6,35 X x + 1,35 X x + 2,4 X x = 20