Question

(2+x) (5+x) = 70 tem que calcular delta

Answer 1

(2+x) (5+x) = 70

10+2x+5x+x² -70 = 0

10+7x+x² -70 = 0

x² + 7x -60 = 0

Answer 2

$<var>\blacktriangleright (2+x) (5+x) = 70 \\\\ \text{Distribuindo:} \\\\ 10 + 2x + 5x + x^2 = 70 \\\\ x^2 + 7x -60 = 0 \\\\ \blacktriangleright a = 1 \\ \blacktriangleright b = 7 \\ \blacktriangleright c = -60 \\ \blacktriangleright \Delta = b^2 - 4ac \\\\ \Delta = 49 - 4 \cdot 1 \cdot (-60) = 49 + 240 \\\\ \Delta = \boxed{289}</var>$