Question

A
4. Dacă x + 2y = 17 şi y - 3z = 4, calculaţi:
a) x + 3y - 3z;
b) 2x + 5y - 3z;
c) (3x + 6y) + (2y - 6z);
5. Adunând descăzutul, scăzătorul si difere
S
d) (2x + 4y) (x + 4y - 62),​

Answer 1

a)x+3y-3z=(x+2y)+(y-3z)=17+4=21

b)(3x+6y)+(2y-6z)=3(x+2y)+2(y-3z)=3x17+2x4=51+8=59

c)2x+5y-3z=2(x+2y)+(y-3z)=2x17+4=38

d)(2x+4y)*(x+4y-6z)=2(x+2y)*[(x+2y)+2(y-3z)]=2x17x(17+8)=34x25=850