Respuesta :

Answer:

Step-by-step explanation:

Part 3 :

We simply expand the brackets

(a+b)² = (a+b)(a+b)

(a+b)(a+b) = a²+ab+ab+b²  = a²+2ab+b²

This is part 3 done

Part 4:

We simply expand 3 brackets now:

(2x-1)³ = (2x-1)(2x-1)(2x-1)

We do the first 2 brackets first:

(2x-1)(2x-1) = 4x²-2x-2x+1 = 4x²-4x+1

Now we multiply this by the last bracket:

(4x²-4x+1)(2x-1) = 8x³ -4x²-8x² +4x+2x -1  = 8x³-12x²+6x-1

This is part 4 done

Hope this helped and brainliest please