9(42) - 9(4) = 9(30) - 9(___)

9(42) - 9(4) = 9(30) - 9(-8)

Step-by-step explanation:

9(42 - 4) = 9(38)

9[30 - (-8)] = 9(38) because of rules of subtracting integers is:

Two like signs become a positive sign

Example:

3+(+2) = 3 + 2 = 5

6−(−3) = 6 + 3 = 9

Two unlike signs become a negative sign

Example:

7+(−2) = 7 − 2 = 5

8−(+2) = 8 − 2 = 6