Question

15x^2-(2x^2+3xy+y^2)-(13x^2-4xy-2y^2),якщоx=1/4;y=-4​

Answer 1

Ответ:

15

Объяснение:

$15x^{2} - ( 2x^{2} + 3xy + y^{2} ) - (13x^{2} - 4xy - 2y^{2} ) = 15x^{2} - 2x^{2} - 3xy - y^{2} - 13x^{2} + 4xy + 2y^{2} = xy + y^{2} = y * ( x + y) = (-4) * (\frac{1}{4} + (-4)) = (-4) * (\frac{1}{4} - 4) = (-4) * \frac{1}{4} - 4 * (-4) = -1 + 16 = 15$