Question

se considera numere reale x,y si z. a) daca xy+xz=10 si x=2 calculati y+z.
b) daca x-y=4 si z=5 calculati xz-yz.
c)1daca xy+xz=20 si y=5 calculati x+z
d) daca xy-xz=24 si y-z=6 calculati x.

Answer 1

a)xy+xz=10
x(y+z)=10
x=2 =>y+z=5

b)xz-yz=z(x-y)
x-y=4 si z=5 =>z(x-y)=20

c)xy+xz=20
x(y+z)=20
x=5 =>y+z=4

d)xy-xz=24
x(y-z)=24
y-z=6 =>6x=24 =>x=4