Question

Giải phương trình

a, 5-2/7x=0

b,3x-5=9-4x

c,3x(x-7)=0

d, (2x+1)(2-3x)=0

Answer 1

a. 5-2/7x=0

<=> -2/7x= -5

<=> x= 35/2

b. 3x-5=9-4x

<=> 3x+4x=9+5

<=> 7x=4

<=> x= 2

c. 3x(x-7)=0

<=> 3x²-21x=0

<=> \(\left[{}\begin{matrix}x=7\\x=0\end{matrix}\right.\)

d.(2x+1)(2-3x)=0

<=> 4x-6x²+2-3x=0

<=> -6x²+x+2=0

<=>\(\left[{}\begin{matrix}x=\frac{2}{3}\\x=\frac{-1}{2}\end{matrix}\right.\)

Answer 2

a. 5-2/7x=0

<=> -2/7x= -5

<=> x= 35/2

b. 3x-5=9-4x

<=> 3x+4x=9+5

<=> 7x=14

<=> x= 2

c. 3x(x-7)=0

<=> 3x²-21x=0

<=>

d.(2x+1)(2-3x)=0

<=> 4x-6x²+2-3x=0

<=> -6x²+x+2=0

<=>