Question

tìm x:a) 6x(3-x)+6x^2-15x=18

b) 4(3x-1)^2=9(x+2)^2

c)x^2+2x=15

Answer 1

\(6x\left(3-x\right)+6x^2-15x=18\)

=>\(18x-6x^2+6x^2-15x=18\)

=>3x=18

=>\(x=\dfrac{18}{3}=6\)

Answer 2

\(6x\left(3-x\right)+6x^2-15x=18\)

\(\Leftrightarrow18x-6x^2+6x^2-15x=18\)

\(\Leftrightarrow3x=18\)

\(\Leftrightarrow x=6\)