Question

stiind ca x+y=-7 si y+z=1, calculati:
a) 3x+3y-1
b) x+2y+z
c) 2x+5y+3z=-7

DAU COROANA

Answer 1

a)3x+3y-1=3(x+y)-1=3×(-7)-1=-21-1=-22

b)x+2y+z=x+y+y+z=-7+1=-6

c)2x+5y+3z=2(x+y)+3(y+z)=2×(-7)+3×1=-14+3=-11