which can be the first step in finding the equation of the line that passes through the points (5,-4) and (-1,8) in slope-intercept form?

What percent of 18 is 24? and plz explain thx.

Find a third-degree polynomial equation with rational coefficients that has roots -2 and 6+i

Whoever gets this right gets the ! the half life of a soul smelling substance is 4 years. if you have 8 oz of this strange substance, how much of it will you have after 20 years? show work.