Question

a) (x + 2y)2 + (x – 2y)(x + 2y);
b) (3x - y)2 – (3x + 5)(3x – 5);
c) (1 - 5y)2 + (1 + 5y)2 – 25y2 – 2;
d) (2 + x)2 + (1 + x)2 – (3 + x)2.
Efectuați, folosind formulele de calcul prescurtat.​

Answer 1

Răspuns:

a)x^2+4xy+4y^2+x^2-4y^2= 2x^2+4xy

b) 9x^2-6xy+y^2-(9x^2-25)=9x^2-6xy+y^2-9x^2+25=y^2-6xy+25

c) 1-10y+25y^2+1+10y+25y^2-25y^2-2= 25y^2

d)