Question

Stiind ca x+3×y=2×y+z=14,calculați a) x+5×y+z b) 3×x+15×y+3×z c)5×x+11×y-2×z d)5×x+19×y+2×z
Repede va rog!​

Answer 1

a)

x+5y+z =(x + 3y) + (2y + z) =14 + 14 =28

b)

3x+15y+3z= 3 • (x+3y) + 3 • (2y + z) =

= 3 • 14 + 3 • 14 =3 • (14+14) = 3•28 =84

c)

5x+11y-2z = 5 • (x+3y) - 2 • (2y+z) =

= 5 • 14 - 2 • 14 = 14 • (5-2) = 14 • 3 =42

d)

5x+19y+2z = 5 • (x+3y) + 2 • (2y+z) =

= 5 • 14 + 2 • 14 = 14 • (5+2) =14 • 7=98