Question

How to solve (2d+6)(3d-15)=0

Answer 1

Given

$\mleft(2d+6\mright)\mleft(3d-15\mright)=0$

We have

$\begin{gathered} 2d+6=0 \\ or \\ 3d-15=0 \end{gathered}$

Then solve each one

$\begin{gathered} 2d+6=0 \\ 2d+6-6=0-6 \\ 2d=-6 \\ \frac{2d}{2}=\frac{-6}{2} \\ d=-3 \end{gathered}$

And

$\begin{gathered} 3d-15=0 \\ 3d-15+15=0+15 \\ 3d=15 \\ \frac{3d}{3}=\frac{15}{3} \\ d=5 \end{gathered}$

Answer: d = -3, d = 5