Answer:
Step-by-step explanation:
Just use FOIL (first, outer, inner, last)
3(x + h)(x + h)
First --> (x)(x) = x^2
Outer --> (x)(h) = xh --> 1xh
Inner --> (h)(x) = xh -->1xh
Last --> (h)(h) = h^2
3(x^2 + 1xh + 1xh + h^2)
3(x^2 + 2xh + h^2)