Question

Which point lies in the plane represented by the equation 2x + 7y + 3z = -25?

(6, 1, –3)
(–3, 3, –2)
(–6, –4, 5)
(6, 1, 2)

Answer 1

You could check each point (the points represent (x,y,z) values)
to check , replace x , y and z in your equation with the numbers for the point you are checking.
for example, to check (6,1,-3) replace x with 6, y with 1 and z with -3 in the equation
2x + 7y + 3z = -25
to get
2*6 + 7*1 + 3*-3 = -25 ?
simplify the left side. If you get -25 then you found a point on the plane (i.e. the answer)