1) (3c-2d)^2 = (3c-2d)(3c-2d)= 3c3c - 3c2d - 2d3c + 2d2d= 9c^2 - 6cd - 6cd + 4d^2= 9c^2 - 12cd + 4d^2
2) (4a-5)(5+4b) = 4a5 + 4a4b - 55 - 54b= 20a + 16ab - 25 - 20b= 20a + 16ab - 20b - 25
1) (3c-2d)^2 = (3c-2d)(3c-2d)
= 3c3c - 3c2d - 2d3c + 2d2d
= 9c^2 - 6cd - 6cd + 4d^2
= 9c^2 - 12cd + 4d^2
2) (4a-5)(5+4b) = 4a5 + 4a4b - 55 - 54b
= 20a + 16ab - 25 - 20b
= 20a + 16ab - 20b - 25