= (1/2)³ - k³ = (1/2 - k)(1/4 +1/2k + k²)
2ху=840
х²+2ху+у²=1369+840
(х+у)²=2209
(х+у)²=47²
х+у=47
х=47-у
2(47-у)у=840
у²-47у+420=0
D=2209-1680=529
y₁=(47+23)/2=35
y₂=(47-23)/2=12
x₁=47-35=12
x₂=47-12=35
Ответ:(12;35) (35;12)
2)<u><em>(x-2)*(x-3)*(x-4)*(x-5) = 24</em></u>
x^2-7x+16=0
x1+x2=7
x1*x2=16
<u><em>x1=1</em></u>
<u><em>x2=6</em></u>
1)(8*(x^2+2x-8))/((4x^2+5x-14)(4x^2+5x-10))=0
x^2+2x-8=0
X1X2=(-2<u>+</u>корінь з 36)/2<u>
</u>1/(4x^2+5x-14)=0
1/(4x^2+5x-10)=0
<em>x=-4</em>
<em>x=2</em>