Answer:
1.) (2x+3)²
= (2x+3)(2x+3)
= 4x²+6x+6x+9
= 4x²+12x+9
2.) (x-5)²
= (x-5)(x-5)
= x²-5x-5x+25
= x²-10x+25
3.) (a+3b-2c)²
= (a+3b-2c)(a+3b-2c)
= a²+3ab-2ac+3ab+9b²-6bc-2ac-6bc+4c²
= a²+3ab+3ab-2ac-2ac+9b²-6bc-6bc+4c²
= a²+6ab-4ac+9b²-12bc+4c²
4.) (3x-1)(3x+1)
= 9x²+3x-3x-1
= 9x²-1
5.) (x+5)³
= (x+5)(x+5)(x+5)
= (x²+5x+5x+25)(x+5)
= (x²+10x+25)(x+5)
= x³+10x²+25x+5x²+50x+125
= x³+10x²+5x²+25x+50x+125
= x³+15x²+75x+125
6.) (x-7)³
= (x-7)(x-7)(x-7)
= (x²-7x-7x+49)(x-7)
= (x²-14x+49)(x-7)
= x³-14x²+49x-7x²+98x-343
= x³-14x²-7x²+49x+98x-343
= x³-21x²+147x-343
