Question

Срочно! Алгебра 7кл. Решить 4(а), 5(а, б)

Answer 1

4
7mn(n²-m²)/[14(m³+n³)]=mn(n-m)(n+m)/[2(m+n)(m²-mn+n²)]=
=mn(n-m)/[2(m²-mn+m²)]
5a
(2x-3y)²/(2x+3y)*(3y-2x)(3y+2x)/(2x-3y)=-(2x-3y)²
5b
1)5/(x=5)+(x²+25)/[(x-5)(x+5)]+5/(x-5)=(5x-25+x²+25+5x+25)/[(x-5)(x+5)]=
=(x²+10x+25)/[(x-5)(x+5)]=(x+5)²/[(x-5)(x+5)]=(x+5)/(x-5)
2)[(x+5)/(x-5)²*(x-5)/(x+5)=x/(x-5)