Question

(4x²-4xy-2y²)-(2x²-5xy+3y²)+5y² при x=¼ y=2
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Answer 1

$(4x^2-4xy-2y^2)-(2x^2-5xy+3y^2)+5y^2=$

$=4x^2-4xy-2y^2-2x^2+5xy-3y^2+5y^2=2x^2+xy$

При  x = 1/4;  y = 2

$2\cdot\bigg(\dfrac14\bigg)^2+\dfrac14\cdot2=\dfrac2{16}+\dfrac12=\dfrac18+\dfrac48=\dfrac58=0.625$

Ответ:  0,625