Question

(a - 3b)² - 4 (a- 3b) - 21​

Answer 1

Step-by-step explanation:

a^2-6ab+9b^2-4a+12b-21

a^2+9b^2-4a+12b-6ab-21

if this equation is equal to zero

than

we got the answer

Answer 2

Answer:

See this answer

Step-by-step explanation:

Answer in above picture