Răspuns:
a₁ = -9 ; a₂ = 15
Explicație pas cu pas:
A (a,-7) ; B (3,-2)
AB² = (3-a)² + [-2 -(-7)]² = 9-6a+a²+25 =>
AB² = a²-6a+34 =>
AB = √(a²-6a+34) = 13 =>
a²-6a+34 = 169 => a²-6a-135 = 0 =>
a₁,₂ = [6±√(36+540)]/2 =>
a₁,₂ = [6±√576]/2 =>
a₁,₂ = [6±24]/2 => a₁ = (6-24)/2 = > a₁ = -9
a₂ = (6+24)/2 => a₂ = 15
#copaceibrainly
