The inequality is looking for a value of "at least 10" gardens. This means something "greater than or equal to" 10 (>=10). After selling 3 on Monday plus 4 on Tuesday, this leaves "x" to be sold to reach the goal. By setting this on the same side as the 7, we can create the inequality to find out how many more are needed, at minimum, to reach our stated goal: 7 + x >= 10, which, when subtracting the 7 out from both sides of the inequality, leaves x >= 3 gardens.