If the total area of the painting and the frame is 58 sq ft, we have the equation:
(8 + 2x)(7 + 2x) = 58
Expanding the equation,
56 + 30x + 4x^2 = 58
Combining like terms and arranging the equation, we have:
4x^2 + 30x - 2 = 0
Therefore, the answer is
C. 4x2 + 30x − 2 = 0