Which of the following is a correct equation for the line passing through the point (-2 1) and having slope m = 1/2

Answer choice A is in slope-intercept (y = mx+b) form. The slope of the line is the number in front of the x, so in this case it's . Now, just plug in the given point to see if the equation is satisfied: 





It works, so answer choice A works.

Answer choice B is in slope-intercept (y = mx+b) form. The slope of the line is the number in front of the x, so in this case it's -2. Answer choice B has the wrong slope, so eliminate B.

Answer choice C is in standard form. Rearrange it to slope-intercept form:





Same as A, so answer choice C works.

Answer choice D is in point-slope form: y - y1 = m(x - x1). If you know this form well, you should be able to see that the given equation satisfies both the slope and point requirement. If you don't know the form well, try putting it into slope-intercept:





Same as A, so answer choice D works.