a)\(\frac{45,2}{Y}+\frac{57,8}{Y}-\frac{71,8}{Y}\)=4,8

\(\frac{\left(45,2+57,8\right)-71,8}{Y}\)=4,8

=\(\frac{103-71,8}{Y}=4,8\)

\(\frac{31,2}{Y}=4,8\)

 Y=\(\frac{31,2}{4,8}\)

Y=6,5.

b)107,8-\(\frac{Y}{9,5}\)=29,2

\(\frac{Y}{9,5}\)=107,8-29,2

\(\frac{Y}{9,5}\)=78,6

Y=78,6 x 9,5

Y=746,7

Bt2 

a)175,84 x 3 -173,4+175,84 x 7 -62,6

=175,84 x (3+7) - (173,4+62,6)

=175,84 x 10 -236

=1758,4-236

=1522,4

b)521,12 x 5 -42,14 x 50+521,12 x 5 -42,14 x 50

=2(521,12 x 5 -42,14 x 50)

= 2 x (5 x (521,12 -42,14 x 10))

=2 x (5 x 99,72)

=2 x 498,6

=997,2.

Cho xin nhá :))

=175,84 x (3+7) - (137,4 +62,6 ) 

= 175,84 x 10 - 200

= 1758,4 -200

= 1558,4

175,84 x 3 - 137,4 + 175,84 x 7 - 62,6

= 175, 84 x ( 3 + 7 ) - ( 137,4 + 62,6 )

= 175,,84 x 10 - 200

= 1785,4 - 200

= 1558,4

175,84 x 3 - 173,4 + 175,84 x 7 - 84,4

=  175,84 x ( 3 +7) - 84,4

=1758,4 - 84 ,4 

=1674

1675

k nhé

1674

k nha

175,84×3-173,4+175,84×7-62,6=349330

521,12×5-42,14×50+521,12×5-42,14×50=199350

k nha ban!

tính trên máy tính ế

y x 8,14 - y x 3,14 = 23,5 

<=> y x ( 8,14 - 3,14 ) = 23,5 

<=> y x 5 = 23,5

<=> y = 4,7

giúp mình cho 5sao  [làm đúng]

a) $175,84x3-173,4+175,84x7-62,6$

= $175,84\times (3+7)-(173,4+62,6)$

= $175,84\times 10-236$

= $1758,4-236$

= $1522,4$

b) $521,12x5-42,14x50+521,12x5-42,14x50$

= $521,12\times (5+5)-42,14\times (50+50)$

= $521,12\times 10-42,14\times 100$

= $5211,2-4214$

= $997,2$

3,14 x 48,7 + 3,14 x 52,3 - 3,14

= 3,14 x (48,7 + 52,3 - 1)

= 3,14 x 100

= 314

=3,14.(48,7+52,3)-3,14

=3,14.11-3,14

=32,4

314

\(a)3,14\times\dfrac{1}{4}+3,14\times99+3,14\times75\%\\ =3,14\times0,25+3,14\times99+3,14\times0,75\\ =3,14\times\left(0,25+99+0,75\right)\\ =3,14\times100\\ =314\)

\(3,14\cdot\dfrac{1}{4}+3,14\cdot99+3,14\cdot75\%\)

\(=3,14\cdot0.25+3,14\cdot99+3,14\cdot0.75\)

\(=3,14\cdot\left(0.25+99+0.75\right)\)

\(=3,14\cdot100\)

\(=314\)