Question

(2x + 4y) × (x + 4y -6z)

Daca x + 2y = 17 si y-3z =4 atunci calculati

Answer 1

   
x + 2y = 17
y - 3z = 4
---
(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] =
= 34 × [17 + 8] = 34 × 25 = 850