Question

Daca x+y+z=17 calculati 5.y+5.x+5.z= 13.x+13.y+13.z-1313= 882-3.(7.x+7.y+7.z)=

Answer 1

$x+y+z=17 \\ a).5y+5x+5z=5(x+y+z)=5 \cdot 17=85 \\ b).13x+13y+13z-1313=13(x+y+z)-1313= \\ =13 \cdot 17-1313=221-1313=-1092 \\ c).882-3(7x+7y+7z)=882-3[7(x+y+z)]= \\ =882-3 (7 \cdot 17)=882-3 \cdot 119=882-357=525$