Question

f: 4(a + b)² – 12(a² – b²) + 9(a - b)²​

Answer 1

Step-by-step explanation:

=4(a+b)²-12(a²-b²)+9(a-b)²

=4(a²+b²+2ab)-12(a²-b²)+9(a²+b²-2ab)

=4a²+4b²+8ab-12a²+12b²+9a²+9b²-18ab

=4a²-12a²+9a²+4b²+12b²+9b²-18ab+8ab

=13a²-12a²+13b²+12b²-10ab

=a²+25b²-10ab

=(a-5b)²

Answer 2

Step-by-step explanation:

4(a+b)²-12(a²-b²)+9(a-b) ²

4(a²+b²+2ab) -12a²+12b²+9(a²+b²-2ab)

13a²+13b²-10ab-12a²+12b²

a²-10ab+25b²