Respuesta :
[tex]\begin{gathered} Step1\colon\mleft(x\mright)\mleft(18x+21\mright)=0 \\ x=\text{ 0 and x=-7/6} \end{gathered}[/tex]
Explanation
[tex]18x^2=-21x[/tex]Step 1
to get the form
[tex]ax^2+bx+c=0[/tex]a) add 21 x in both sides
[tex]\begin{gathered} 18x^2=-21x \\ 18x^2+21x=-21x+21x \\ 18x^2+21x=0 \\ so\text{ a=18, b=21, c=0} \end{gathered}[/tex]Step 2
now, factorize the left hand side of the equation
[tex]\begin{gathered} 18x^2+21x=0 \\ (x)(18x+21)=0 \\ so\text{, the factors are x and (18x+21)} \end{gathered}[/tex]now, to get zero from those factors
[tex]\begin{gathered} (x)(18x+21)=0 \\ x=\text{ 0} \\ or \\ 18x+21=0 \\ \text{subtract 21 in both sides} \\ 18x+21-21=0-21 \\ 18x=-21 \\ \text{divide both sides by 18} \\ \frac{18x}{18}=\frac{-21}{18} \\ x=-\frac{21}{18}=-\frac{7}{6} \\ x=-\frac{7}{6} \end{gathered}[/tex]so, the answer is
[tex]x=\text{ 0 and x=-7/6}[/tex]I hope this helps you
