\(a,=69,78\times\left(\dfrac{3}{4}+\dfrac{1}{4}+99\right)\\ =69,78\times\left(\dfrac{4}{4}+99\right)\\ =69,78\times\left(1+99\right)=69,78\times100=6978\\ b,34,1\times8+34,1\times0,5\\ =34,1\times\left(8+0,5\right)\\ =34,1\times8,5\\ =289,85\)

a: =69,78(3/4+1/4+99)

=69,78*100

=6978

b: =34,1(8+0,5)=34,1*8,5=289,85

=0,8x2x48+1,6x2+1,6x50

=1,6x48+1,6x2+1,6x50

=1,6x(48+2+50)

=1,6x100

=160

a: \(0,8\times96+1,6\times2+1,6\times50\)

\(=1,6\times48+1,6\times2+1,6\times50\)

\(=1,6\times\left(48+2+50\right)=1,6\times100=160\)

b: \(1,47\times3,6+1,47\times6,4\)

\(=1,47\times\left(3,6+6,4\right)\)

=1,47x10

=14,7

c: \(69,78\times75\%+69,78\times\frac14+69,78\times99\)

\(=69,78\times\left(0,25+0,75+99\right)\)

=69,78x100

=6978

69,78+35,97x3,2:1,5

=1x\(\left(69,78+35,97\right)\)x3,2:1,5

=1x105,75x3,2:1,5

=317,25:1,5

=211,5

69,78  x 75 % + 69,78  x 1/4 +  69,78  x 1/4

= 69,78  x 3/4 + 69,78  x 1/4 +  69,78  x 1/4

= 69,78 x ( 3/4 + 1/4 + 1/4 )

=69,78 x 1,25 (hoặc 5/4)

= 87,225

\(\frac{72}{99}-\frac{28}{99}-\frac{14}{99}=\frac{72-28-14}{99}\)\(=\frac{30}{99}=\frac{10}{33}\)

\(\left(69,78+30,22\right)+35,97\)\(=100+35,97=135,97\)

\(83,45-\left(30,98+42,47\right)\)\(=83,45-73,45=10\)

72/99-28/99-14/99

=72/99-(28/99+14/99)

=72/99-42/99

=30/99=10/33

67,78+35,97+30,22

=(67,78+30,22)+35,97

=98+35,97

=133,97

83,45-30,98-42,47

=83,45-(30,98+42,47)

=83,45-73,45

=10

69,78 + 35,97 + 30,22 = (69,78 + 30,22) + 35,97=100 + 35,97=135,97

(  69,78+30,22)+35,97

100+35,97

135,97

cho m nha

a) \(\dfrac{7}{11}+\dfrac{3}{4}+\dfrac{4}{11}+\dfrac{1}{4}=\left(\dfrac{7}{11}+\dfrac{4}{11}\right)+\left(\dfrac{3}{4}+\dfrac{1}{4}\right)=1+1=2\)

b) \(\dfrac{72}{99}-\dfrac{28}{99}-\dfrac{14}{99}=\dfrac{72-28-14}{99}=\dfrac{30}{99}=\dfrac{10}{33}\)

a) 7/11+3/4+4/11+1/4

=(7/11+4/11)+(3/4+1/4)

=     1           +    1

=          2.

b) 72/99-28/99-14/99

=72/99-(28/99+14/99)

=72/99-      42/99

=     30/99=10/33.

c) 69,78+35,97+30,22

=(69,78+30,22)+35,97

=      100          +35,97

=                 135,97.

d) 83,45-30,98-42,47

=83,45-(30,98+42,47)

=83,45-      73,45

=        10.

a) 2

b) 10/33

c) 135,97

d) 10