Odpowiedź:
a) (x+5)*(x+7)-30=x do kwadratu +7x+5x+35-30=x do kwadratu +12x+35-30=x do kwadratu+12x+5
b) 10+x-(1+2x)*(x-4)=10+x-(x-4+2x do kwadratu - 8x)=10+x-(-7x-4+2x do kwadratu)=10+x+7x+4-2x do kwadratu=14+x+7x-2x do kwadratu=14+8x-2x do kwadratu= -2x do kwadratu+8x+14
c) (7x-2)*(3-5x)-4(1-2x)*(0,5x+0, 25)=21x-35x do kwadratu-6+10x-4(1-2x)*(0,5x+0,25)=21x- 35x do kwadratu-6+10x+(-4+8x)*(0,5x+0,25)=21x-35x do kwadratu-6+10x-2x-1+4x do kwadratu+2x=21x-35x do kwadratu-6+10x-1+4x do kwadratu=31x-35x do kwadratu-6-1+4x do kwadratu=31x-31x do kwadratu-6-1=31x-31x do kwadratu-7=31x-31x do kwadratu-7
