Subtracting a negative number is like removing debt. When you remove debt, you effectively gave someone money and the value of their bank account increased.
Another answer is that “subtraction is addition of the opposite,” so subtracting a negative number is really adding a positive number, which again causes the other number to increase.
The area of the rectangle:
A = Length x Width = JK x KL = 36 cm²
If JK ≥ 4 cm, we have to prove that KL ≤ 9 cm.
Answer:
Assume that a. KL > 9 cm.
Then the area of rectangle JKLM is greater than b. 36 cm²,
which contradicts the given information that c. side is at least 4 cm long.
So the assumption must be false. Therefore, d. KL ≤ 9 cm.