II gimnazjum

Policzmy to razem 2

a) (5x+4)(x2−3x+2)=    =5x(x2−3x+2)+4(x2−3x+2)=    =5x3−15x2+10x+4x2−12x+8=    =5x3−11x2−2x+8 &nbsp; b) (8−2y)(3y3+4y2−y)=

a) (2x−y)(3x+2y)−(2x+y)(3x−2y)=    =6x2+4xy−3xy−2y2−(6x2−4xy+3xy−2y2)=    =6x2+xy−2y2−(6x2−xy−2y2)=    =6x2+xy−2y2−6x2+xy+2y2=    =2xy

a) 5x(x+1)(x−2)= &nbsp; (5x2+5x)(x−2)= &nbsp;    =5x3−10x2+5x2−10x= &nbsp; 5x3−5x2−10x &nbsp; &nbsp; b) 3x(2x2−1)(5x+2)=

P1​=(x+2)(x+2)=x(x+2)+2(x+2)= &nbsp;    =x2+2x+2x+4=

a) (5−m)2=52−2⋅5⋅m+m2=25−10m+m2 &nbsp; &nbsp; b) (4y−3x)2=(4y)2−2⋅4y⋅3x+(3x)2= &nbsp;    =16y2−24xy+9x2

a) (x−5y)(x+5y)=x2−(5y)2=x2−25y2 b) (3x2−1)(3x2+1)=(3x2)2−12=9x4−1