Since you are asking for "an equation", the point-slope equation of a line is a suitable choice.
For slope m and point (h, k), the equation of a line can be written
... y -k = m(x -h)
For your values, this is
... y +2 = (4/5)(x -2)
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There are many other forms this equation could take. You can multiply by 5 and subtract the left side to put it into general form.
... 4x -5y -18 = 0
And you can add the opposite of the constant to put it into standard form.
... 4x -5y = 18
A favorite of many people is slope-intercept form, which you can find by solving any of these for y.
... y = (4/5)x - 18/5
