Răspuns:
x + 2y = 17
y - 3z = 4
a) x + 3y - 3z = x + 2y + y - 3z =
= (x + 2y) + (y - 3z) = 17 + 4 = 21
b) 2x + 5y - 3z = 2x + 4y + y - 3z =
= 2 · (x + 2y) + (y - 3z) = 2 · 17 + 4 = 38
c) (3x + 6y) + (2y - 6z) = 3 · (x + 2y) + 2 · (y - 3z) = 3 · 17 + 2 · 4 = 59
d) (2x + 4y) · (x + 4y - 6z) = 2 · (x + 2y) · (x + 2y + 2y - 6z) =
= 2 · (x + 2y) · [(x + 2y) + 2 · (y - 3z)] =
= 2 · 17 · (17 + 2 · 4) = 2 · 17 · 25 = 850
Explicație pas cu pas:
