Question

tìm số tự nhiên x, biết :

2⁴ . x - 3² . x= 145 - 255 : 51 

5 ( x + 35 ) - 2³ . 5² = 2⁵ . 3² - 3.31

Answer 1

x(2⁴-3²)=145-5

\(\Leftrightarrow\)7x=140

\(\Leftrightarrow\)x=20

5(x+35)-200=288-93

\(\Leftrightarrow\)5(x+35)=288+200-93=395

\(\Leftrightarrow\)x+35=79

\(\Leftrightarrow\)x=44

 

Answer 2

a, Lời giải 

\(x\left(2^4-3^2\right)=145-5\)

\(\Leftrightarrow7x=140\)

\(\Leftrightarrow x=140:7\)

\(\Rightarrow x=20\)

b, Lời giải 

\(5\left(x+35\right)-200=288-93\)

\(\Leftrightarrow5\left(x+35\right)=395\)

\(\Leftrightarrow x+35=395:5\)

\(\Leftrightarrow x+35=79\)

\(\Leftrightarrow x=79-35\)

\(\Rightarrow x=44\)