tim m m.n giup dum nhe

N

nguyenbahiep1

tim m de :5^2x - 5.5^x - 2.m.5^x +m^2 +5m >0, voi moi x thuoc R

[laTEX]5^x = t > 0 \\ \\f(t) = t^2 - (5+2m)t + m^2+5m > 0 \forall t > 0 \\ \\ \Delta = 4m^2 + 20m + 15 - 4m^2 -20m = 25 > 0 \\ \\ t_1 = m \\ \\ t_2 = m+5 \\ \\ f(t) > 0 \forall t > 0 \Rightarrow t_1 < t_2 < 0 \Rightarrow m+5 < 0 [/laTEX]
 
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