<span>p(2-s)=st^3
2p -ps =st^3
2p =ps+st^3
2p =s(p+t^3)
s =2p/(p+t^3)</span>
<span>42/7a-a^2-6/a=42/7a-7a^2-42/7a=42-7a^2-42/7a=-7a/7=-a,при а=2 Ответ:а=-2</span>
X + y = 63
x - y = 19
------------------ +
2x = 82
x = 41
y = 63 - x = 63 - 41 = 22
Ответ
41; 22
(a-2a+1)*(ab/(a-b)) = (1-a)*ab / (b-a)