Question

Tìm x:

x² -7x + 10 = 0

Answer 1

x² -7x + 10 = 0

=> x² - 2x - 5x + 10 = 0

=> x(x - 2) - 5(x - 2) = 0

=> (x - 5)(x - 2) = 0

=> \(\left[\begin{array}{nghiempt}x-5=0\\x-2=0\end{array}\right.\)   => \(\left[\begin{array}{nghiempt}x=5\\x=2\end{array}\right.\)

Vậy x = 2 hoặc x = 5

Answer 2

x² - 7x + 10 = 0

=> x² - 2x - 5x + 10 = 0

=> ( x² - 2x ) - ( 5x - 10 ) = 0

=> x( x - 2 ) - 5( x - 2 ) = 0

=> ( x - 2 ) . ( x - 5 ) = 0

Ta có:    x - 2 = 0

           => x = 2

hoặc      x - 5 = 0

            => x = 5

Vậy x = 2 hoặc x = 5

Answer 3

x² - 7x + 10 = 0

\(\Rightarrow\) (x - \(\frac{7}{2}\))² - \(\frac{9}{4}\) = 0

\(\Rightarrow\) (x - \(\frac{7}{2}\))² = \(\frac{9}{4}\)

\(\Rightarrow\) x - \(\frac{7}{2}\) = \(\frac{3}{2}\)

\(\Rightarrow\) x = 5

 

Answer 4

2 or 5

Answer 5

2

5