(x + 3y)² = x² + 6xy + 9y²
(xy + 2y)² = x²y³ + 4xy² + 4y²
(x + 6y)² = x² + 12xy + 36y²
(x + 9y)²=x² + 18xy + 81y²
(11x + 5y)²=121x² + 110xy + 25y²
(x + 2y)² = x² + 4xy + 4y²
(7x + 2y)² = 49x² + 28xy + 4y²
(8 + 9x)² = 64 + 144x + 81x²
(2x + 3y)² = 4x² + 12xy + 9y²
(5x + 2y)² = 25x² + 20y+4y²
exemplu cu rezolvare completa:
(3x +2 )²= 9x² + 12x + 4
9x² + 12x + 4
Δ=144-4×4×9
Δ=144-144=0
x₁=(-b+√Δ)/2a=(-12+0)/2 = - 6
x₂=(-b-√Δ)/2a=(-12-0)/2 = - 6
