Hey there!
14 - ? = 2^3 + 5
14 - x = 2^3 + 5
14 - x = 2 * 2 * 2 + 5
14 - x = 4 * 2 + 5
14 - x = 8 + 5
14 - x = 13
-x + 14 = 13
SUBTRACT 14 to BOTH SIDES
-x + 14 - 14 = 13 - 14
SIMPLIFY IT!
-x = 13 - 14
-x = -1
-1x = -1
DIVIDE -1 to BOTH SIDES
-1x/-1 = -1/-1
SIMPLIFY IT!
x = -1/-1
x = 1
Therefore, your mystery number should be: 1
Good luck on your assignment & enjoy your day!
~Amphitrite1040:)