Răspuns :
xy=30
xz=25
calculaţi x(y+z) ,
dar xy+xz=x(y+z)
⇒x(y+z) = 25+30 = 55 .
x(y-z) = xy-xz
= 30-25
= 5 .
xz=25
calculaţi x(y+z) ,
dar xy+xz=x(y+z)
⇒x(y+z) = 25+30 = 55 .
x(y-z) = xy-xz
= 30-25
= 5 .