Ano ang halaga ng x na ibinigay na (x + 3) / (x + 7)> 3?

Sagot:

Ang solusyon ay #x sa (-9, -7) #

Paliwanag:

Hindi mo maaaring tumawid

Ang di-pagkakapantay-pantay ay

# (x + 3) / (x + 7)> 3 #

#=>#, # (x + 3) / (x + 7) -3> 0 #

#=>#, # (x + 3-3 (x + 7)) / (x + 7) #

#=>#, # (x + 3-3x-21) / (x + 7)> 0 #

#=>#, # (- 2x-18) / (x + 7)> 0 #

#=>#, # (2 (x + 9)) / (x + 7) <0 #

Hayaan #f (x) = (2 (x + 9)) / (x + 7) #

Gumawa tayo ng tsart ng pag-sign

#color (white) (aaaa) ## x ##color (white) (aaaa) ## -oo ##color (white) (aaaa) ##-9##color (white) (aaaa) ##-7##color (white) (aaaa) ## + oo #

#color (white) (aaaa) ## x + 9 ##color (white) (aaaaaa) ##-##color (white) (aaaa) ##+##color (white) (aaaa) ##+#

#color (white) (aaaa) ## x + 7 ##color (white) (aaaaaa) ##-##color (white) (aaaa) ##-##color (white) (aaaa) ##+#

#color (white) (aaaa) ##f (x) ##color (white) (aaaaaaa) ##+##color (white) (aaaa) ##-##color (white) (aaaa) ##+#

Samakatuwid, #f (x) <0 # kailan #x sa (-9, -7) #

graph {(x + 3) / (x + 7) -3 -26.83, 9.2, -8.96, 9.06}