Question

Si: a + b = 20 ; a 2 + b 2 = 150. Calcular: ab

Answer 1

Si: a + b = 20 ; a 2 + b 2 = 150. Calcular: ab

formula:

$(a+b)^{2} = a^{2} + 2(a)(b) + b^{2}$

remplazamos:

$20^{2} = a^{2} +b^{2} + 2(a)(b)$

400 = 150 + 2(a)(b)

400 - 150 = 2ab

250 = 2ab

ab  = 125

respuesta :     125