You would add because that is just how i thought of it
surface area = 4 x pi x r^2
diameter = 1 so radius = 1/2 = 0.5
4 x 3.14 x 0.5^2 = 3.14 meters^2
Put an equal sign between the two expressions, and solve for x
4+(−7) is 7 units from 4, in the negative direction (that is, to the left of 4)
