x^3*y^3=343
x*y=7
учитывая это преобразуем [x^2+y^2]^2=17^2,
x^4+2x^2*y^2+y^4=289
x^4+y^4=289-2*[xy]^2=289-2*7^2=289-98=191
ответ:191
<span>0.64-4k^2=(0.8-2k)(0.8+2k)</span>
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P = 25
5×+ 5× + × = 25
11 × = 25
× = 2 (7)
2 (7) × 5 =11 (3)