multiply (x+3)^2?

(x+3)² = (x+3).(x+3) = x*x + x*3 + 3*x +3*3 = x²+3x+3x+9 = x²+6x+9


when we have (a+b)² we say : its the sqare of the first a² more the two times the first times the second 2ab more the sqare of the second

(a+b)² = a² + 2ab+b²

(x+3) *(x+3 )

Use the foil method to find the trinominal.
F: first.
x * x = x^2.
O: outside.
3x
I: inside
3x:
L: last
3 * 3 = 9

put it all together:

x^2 + 6x + 9.

try (x+3)(x+3)

6x