write the equation of the line that passes through each pair of points in slope-intercept form. (3,4),(4,6)

First, get the slope  = m =  [6 - 4] / [ 4 - 3]  =  [2] / [1]   = 2

Using this and one of the points - I'll choose (3,4) -  we can write

y - y₁  = m(x - x₁)

y - 4 = 2 (x - 3)

y = 2x - 6 + 4

y = 2x - 2       and that's in slope-intercept form