Answer:
99
Step-by-step explanation:
You can solve it by Squaring/multiply 18 by itself and 15 by itself then subtract them both:
(18 × 18) - (15 × 15)
324 - 225
99
You could also do difference of two squares:
(x² - y²)
= (x + y) (x - y)
= (18 + 15) (18 - 15)
= (33) (3)
= 99
