Răspunsuri

2014-05-18T23:13:09+03:00
⇒(5/6) la puterea 1-2x=(5/6) la puterea -2-x⇒
1-2x=-2-x⇒   -2x+x=-2-1⇒    -x=-3   ·(-1)⇒
x=3
S={3}
2)    ⇒0,5 se poate scrie 5/10 simplificam=1/2=2la puterea -1
8/√2=rationalizam=8√2/2 simplificam=4√2=2²·2la puterea1/2=2la puterea 2+1/2=2la puterea =5/2
(2) la puterea -( x²-9x+17,5)=2la puterea 5/2
-x²+9x-17,5=5/2
-x²+9x-17,5=2,5
-x²+9x-17,5-2,5=0     ·(-1)
x²-9x+20=0
Δ=81-80=1
X1=9-1/2=8/2=4
X2=9+1/2=10/2=5