Question

imi poti spune cum ar trebui sa fac?​

Answer 1

Răspuns:

Explicație pas cu pas:

x² - 4x - a = 0

x₁+x₂ = 4/1 = 4

x₁x₂ = -a/1 = -a

x₁+x₂+3x₁x₂ = -2  =>

4-3a = -2  => 3a = 6  => a = 2

A(2 , 2) ; B(8 , 2) ; C(8 , 10)   ; P = AB+AC+BC

AB² = (Xb - Xa)² + (Yb - Ya)²

AB² = (8-2)²+(2-2)² = 36 => AB = 6 u.m.

AC² = (8-2)²+(10-2)² = 36+84 = 100 => ac = 10 u.m.

BC² = (8²-8²)+(10-2)² = 64 => BC = 8 u.m.

P = 6 + 10 + 8 = > P =24 u.m.