Giúp mình với

a) \(\left(2,4-3x\right).0,5=0,9\)

\(2,4-3x=0,9:0,5\)

\(2,4-3x=1,8\)

\(3x=2,4-1,8\)

\(3x=0,6\)

\(x=0,6:3\)

\(x=0,2\)

b) \(\left(8,8x-50\right):0,4=51\)

\(8,8x-50=51.0,4\)

\(8,8x-50=20,4\)

\(8,8x=20,4+50\)

\(8,8x=70,4\)

\(x=70,4:8,8\)

\(x=8\)

c) \(\left(0,472-x\right):2=1,634\)

\(0,472-x=1,634.2\)

\(0,472-x=3,268\)

\(x=0,472-3,268\)

\(x=-2,796\)

d) \(1,6-\left(x-0,2\right)=6,5\)

\(x-0,2=1,6-6,5\)

\(x-0,2=-4,9\)

\(x=-4,9+0,2\)

\(x=-4.7\)

\(a.2,4-3x=1,8\)

\(3x=0,6\)

\(x=0,2\)

\(b.8,8x-50=20,4\)

\(8,8x=70,4\)

\(x=8\)

\(c.0,472-x=3,268\)

\(x=-2,796\)

\(d.x-0,2=-4,9\)

\(x=-4,7\)

a) \(\left(2,4-3x\right).0,5=0,9\)

\(\Rightarrow\left(2,4.3x\right)=0,9:0,5\)

\(\Rightarrow2,4.3x=0,45\)

\(\Rightarrow3x=0,45:2,4\)

\(\Rightarrow3x=\dfrac{3}{16}\)

\(\Rightarrow x=\dfrac{1}{16}\)

b)\(\left(8,8x-50\right):0,4=51\)

\(\Rightarrow\left(8,8x-50\right)=51.0,4\)

\(\Rightarrow8,8x-50=\dfrac{255}{3}\)

\(\Rightarrow8,8x=135\)

\(\Rightarrow x=135:8,8\)

\(\Rightarrow x=\dfrac{675}{44}\)

a, 2,67 : 0,25 + 2,67 x 3 + 2,67 : 0,5 + 26,7 x 0,1

= 2,67 x 4 + 2,67 x 3 + 2,67 x 2 + 2,67 x 1

= 2,67 x (4 + 3  + 2 + 1)

= 2,67 x 10

= 26,7

Tui ko biết ?

6,5 : 0,25 + 2 x 6,5 + 6,5 x \(\dfrac{100}{25}\)

= 6,5 x 4 + 2 x 6,5 + 6,5 x 4

= 6,5 x (4 + 2 + 4)

= 6,5 x 10

= 65

= 6,5 x 4 + 2 x 6,5 + 6,5 x 4 

= 6,5 x ( 4 + 2 + 4 )

= 6,5 x 10 

65

ratg gsvs bsnb bzn zh svhs smsm sns c xbx ja js s nx xhxxb same gj hbgg  jcu buyxcvyt u

53644

như thế ai lm nổi

trốc tru vừa thôi

tính bằng cách thuận tiện nhất:

  6,5 x 7+ 6,5 : 0,2 + 6,5 : 0,125

=  6,5 x 7+ 6,5/0,2 + 6,5/0,125

= 45,5 + 32,5 + 52

= (45,5 + 32,5) + 52

= 130

Chúc bạn học tốt!

y x 6,5 + y : 2 = 71,4

y x 6,5 + y x 1/2 = 71,4

y x ( 6,5 + 1/2) = 71,4

y x ( 6,5 + 0,5) = 71,4

y x 7 = 71,4

y = 71,4 : 7

y = 10,2

\(y\times6,5+y:2=71,4\\ y\times6,5+y\times\dfrac{1}{2}=71,4\\ y\times6,5+y\times0,5=71.4\\ y\times\left(6,5+0,5\right)=71,4\\ y\times7=71.4\\ y=71,4:7\\ y=10,2\)