Question

Упростите выражение и найдите его значение при = −7,65; = 3 13/20 x(x+2y)+y^2-(x+y)(x^2-xy+y^2)(x-y)(x+y)x+xy^2+y^3

Answer 1

х+у=-7.65+3.65=-4; (х-у)=-7.65-3.65=-11.3

x(x+2y)+y²-(x+y)(x²-xy+y²)(x-y)(x+y)x+xy²+y³=

(х²+2ху+у²)-(x²-y²)*(x³+y³)*х+у²(х+у)=(х+у)²-(x²-y²)(x³+y³)*х+у²(х+у)=

(х+у)((х+у)-(х-у)*х(х³+у³)+у²)=(-4)(-7.65*(-11.3)(-1)(7.65³+3.65³)+3.65²)=

(-4)(-86.445(447.697125+48.627125)+13.3225)=

(-4)(-86.445(496.32425)+13.3225)=(-4)(-42904.74979+13.3225)=4*42891.42729=171565.70916