1.Produsul numerelor: (√78-√8)*(√50-√32)
(√78-√8)*(√50-√32)=
= (√2*39-2√2)*(5√2-4√2)=
= (√2*39-2√2)*√2=
=2√39-4
2.Numaru: (5√72-2√18+3√32):√8 calculat este?
(5√72-2√18+3√32):√8 =
=(30√2-6√2+12√2):2√2 =
=36√2:2√2 =18
3. (21x³ - 14x² +7):(-7x)+(x-1)(x+2)=
=-3x² + 2x -1+x²+x-2=
=-2x² + 3x -3