Răspuns:
a) 21x+27
b) x²+1
c) y²
Explicație pas cu pas:
a) 3x(x²+2x+1)-(2x-3)(4x²+12x+9)+5x²+6x² =
= 3x³+6x²+3x-(8x³+24x²+18x-12x²-36x-27)+5x³+6x² =
= 3x³+6x²-3x-(8x³+12x²-18x-27)+5x³+6x² =
= 3x³+6x²-3x-8x³-12x²+18x+27+5x³+6x² =
= 0+0+21x+27 =
=21x+27
b) -2x³+2x²-2x-2x²-2x+(x+1)²+2x³+2x =
= -2x+(x+1)² =
= -2x+x²+2x+1 =
= x²+1
c) 22x²-33x-25x²÷(-5x)+(2x+y)²-4x²-4xy-22x²+28x =
= 22x²-33x+5x+(2x+y)²-4x²-4xy-22x²+28x =
= -33x+5x+(2x+y)²-4x²-4xy+28x =
= -33x+5x+4x²+4xy+y²-4x²-4xy+28x =
= -33x+5x+y²+28x =
= 0+y² =
= y²
