Question

1. combine like terms -3c + 9j + 5c - 12j

Explanation:

Step1: Group like terms

Group the terms with \( c \) and the terms with \( j \) together: \((-3c + 5c)+(9j - 12j)\)

Step2: Combine like terms for \( c \)

For the \( c \) terms: \(-3c + 5c = 2c\)

Step3: Combine like terms for \( j \)

For the \( j \) terms: \(9j - 12j=-3j\)

Step4: Write the final result

Combine the results from Step 2 and Step 3: \(2c - 3j\)

Answer:

$2c - 3j$