\(a,50\%x-0,2+x=\dfrac{4}{5}\)

\(\Leftrightarrow\dfrac{1}{2}x-0,2+x=\dfrac{4}{5}\)

\(\Leftrightarrow\dfrac{1}{2}x+x=\dfrac{4}{5}+0,2\)

\(\Leftrightarrow\dfrac{3}{2}x=\dfrac{4}{5}+\dfrac{1}{5}\)

\(\Leftrightarrow\dfrac{3}{2}x=1\)

\(\Leftrightarrow x=\dfrac{2}{3}\)

\(b,\left(x-\dfrac{3}{4}\right):\dfrac{1}{2}+\dfrac{3}{2}=\dfrac{25}{2}\)

\(\Leftrightarrow\left(x-\dfrac{3}{4}\right).2=\dfrac{25}{2}-\dfrac{3}{2}\)

\(\Leftrightarrow\left(x-\dfrac{3}{4}\right).2=\dfrac{22}{2}\)

\(\Leftrightarrow x-\dfrac{3}{4}=11:2\)

\(\Leftrightarrow x=\dfrac{11}{2}+\dfrac{3}{4}\)

\(\Leftrightarrow x=\dfrac{25}{4}\)

4 x 25 x 0,25  x 1/5 x 1/2 x  2

= 4 x 25 x 0,25 x 0,2 x 0,5 x 2

= 5

100 . 0,25 . 1/5 . 1/2 . 2

25 . 1/5 . 1/2 . 2

5/1 . 1/2 . 2

5/2 . 2

10/2 = 5

5 nhaaa

1. (x-3)²

2. (3y+2x)²

3. (1/5x-8y)(1/5x+8y)

4. (x-2y)(x²+2xy+4y²)

5. (4x-3-x-1)(4x-3+x+1)

(3x-4)(5x-2)

23/12

1/3

a.x=23/12

b.x=1/3

x = 5/3+1/4

x = 23/12

x = 1/2 x 2/3

x= 1/3

c

C

C

\(\dfrac{14}{3}-\dfrac{5}{2}=\dfrac{14\cdot2-5\cdot3}{6}=\dfrac{13}{6}\)

\(\dfrac{14}{3}\) - \(\dfrac{5}{2}\) = \(\dfrac{28}{6}\) - \(\dfrac{15}{6}\) = \(\dfrac{13}{6}\)

\(\dfrac{14}{3}-\dfrac{5}{2}=\dfrac{28}{6}-\dfrac{15}{6}=\dfrac{13}{6}\)

a) Ta có: 2x+33=-11

nên 2x=-44

hay x=-22

b) Ta có: \(\dfrac{x}{2}=\dfrac{-49}{14}\)

nên x=-7

c) Ta có: \(\dfrac{5}{6}x+\dfrac{10}{3}=\dfrac{7}{2}\)

nên \(\dfrac{5}{6}x=\dfrac{7}{2}-\dfrac{10}{3}=\dfrac{1}{6}\)

hay \(x=\dfrac{1}{6}:\dfrac{5}{6}=\dfrac{1}{5}\)

-(x-5)^2<=0

=>B<=3

Dấu = xảy ra khi x=5