Answer:
9x² + 6xy + y²
Explanation:
(a + b)² = a² + 2ab + b²
a = 3x
b = y
(3x +y)² = (3x)² + 2*3x*y + y²
= 9x² + 6xy + y²
(3x)² = 3²*x² = 3*3*x² = 9x²
5.3m questions
6.9m answers