a. ( 48 x 0,75 - 240 : 10 ) - ( 16 x 0,5 - 16 : 4 )

=(36-24)-(8-4)

=12-4

=8

b. (1000 x 0,1 - 900 x 0,1 - 90 x 0,1 ) x ( 142 x 0,5 - 240 x 0,25 )

=(100-90)x(71-60)

=10x11

=110

# mui #

a 

= ( 24 + 12 ) - ( 9 - 4 ) 

= 36 - 5 

= 31 

a) 5/3 : 0,5 = 4/3 : 0,1 . x

10/3 = 40/3.x

x = 1/4

b) 18¹⁶ = 2x.3³²

2¹⁶.(3²)¹⁶ = 2x .3³²

2¹⁶.3³² = 2x.3³²

=> 2¹⁶ = 2.x

=> x = 2¹⁶ : 2 = 2¹⁵

\(a.\frac{5}{3}:0,5=\frac{4}{3}:0,1\times x\)

\(\Leftrightarrow\frac{4}{3}:0,1\times x=\frac{10}{3}\)

\(\frac{4}{3}:0,1=\frac{10}{3}:x\)

\(\frac{40}{3}=\frac{10}{3}:x\)

\(\Rightarrow x=\frac{10}{3}:\frac{40}{3}\)

\(x=\frac{1}{4}\)

\(b.18^{16}=2x.3^{32}\)

\(2^{16}.\left(3^{16}\right)^2=2x.3^{32}\)

\(2^{16}.\left(3^{32}\right)=2x.3^{32}\)

\(2^{16}=2x\)

\(\Rightarrow x=2^{16}:2\)

\(x=2^{15}\)

\(\)

a) \(\dfrac{x}{-6}=\dfrac{-15}{45}\)

    \(\dfrac{-x}{6}=\dfrac{-15}{45}\)

    \(\dfrac{x}{6}=\dfrac{15}{45}\)

    \(x=\dfrac{\left(15\cdot6\right)}{45}\)

    \(x=2\)

b) \(\dfrac{x}{5}=\dfrac{16}{25}\)

    \(x=\dfrac{\left(16\cdot5\right)}{25}\)

    \(x=\dfrac{80}{25}\)

   \(x=\dfrac{16}{5}\)

c) \(\dfrac{5}{x-3}=\dfrac{20}{-12}\)

  \(x-3=\dfrac{\left(5\cdot-12\right)}{20}\)

 \(x-3=-3\)

 \(x=\left(-3\right)+3\)

\(x=0\)

d) \(\dfrac{2}{5}\cdot x=\dfrac{6}{35}\)

         \(x=\dfrac{6}{35}\div\dfrac{2}{5}\)

        \(x=\dfrac{3}{7}\)

thiên tài cũng phát ngất

Đáp án C

Đáp án: C.

\(\dfrac{7}{8}-\dfrac{1}{4}\cdot\dfrac{5}{2}=\dfrac{x}{16}\)

=>\(\dfrac{x}{16}=\dfrac{7}{8}-\dfrac{5}{8}=\dfrac{2}{8}=\dfrac{1}{4}\)

=>\(x=\dfrac{16}{4}=4\)

=>Chọn A

B

b

B

\(\frac{0,5}{0,7}\)=\(\frac{-0.1}{5.x}\)

→(0,5).5.x=-0,07

2,5.x=0,07

x=0,028

\(\frac{1,2}{x+3}\)=\(\frac{5}{4}\)

→5x+15=4,8

5x=-10,2

x=-2.04