Question

Which of the following equations is perpendicular to y = -4x + 10?

Answer 1

when the equations are of the form \(y=\color{brown}mx+b\)
\(\color{brown}m\) is the slope.


two equations of lines
\(y=\color{brown}{m_1}x+b_1\)

\(y=\color{brown}{m_2}x+b_2\)


lines will have perpendicular slopes when
\[\color{brown}{m_1m_2}=-1\]
or equivalently \[\color{brown}{m_1}=-\frac1{\color{brown}{m_1}}\]