Which polynomial has the incorrect factored result 5xy15x6y1

Which polynomial has the incorrect factored result.

5xy-15x-6y+18 = 5x(y-3) – 6(y+3)

6a²+9ab²+6ab+9b³ = 3a(2a+3b²) + 3b(2a+3b²)

30x-15 = 15(2x-15)

Solution

i) 5xy-15x-6y+18 = 5x(y-3) – 6(y+3)

LHS = 5xy-15x-6y+185x(y -3) -6(y-3)

So, incorrect factorisation

ii) 6a^2+9ab^2+6ab+9b^3 = 3a(2a+3b2) + 3b(2a+3b2)

LHS 6a^2+9ab^2+6ab+9b^3 = 3a(2a +3b^2) + 3b(2a +3b^2)

Correct factorisation

iii) 30x-15 = 15(2x-15)

30x-15 = 15(2x -1)

So, incorrect factorisation