Question

Lim x стремится к 7 2x^2-13x-7/x^2-9x+14=

Answer 1

lim((2x²-13x-7)/(x²-9x+14))=(2*7²-13*7-7)/(7²-9*7+14)=0/0
x->7

2x²-13x-7=0. 2x²-13x-7=2*(x+1/2)*(x-7)
x²-9x+14=0,   x²-9x+14=(x-2)*(x-7)

lim([2*(x+1/2)*(x-7)] / [(x-2)*(x-7)])=lim((2x-1)/(x-2))=(2*7+1)/(7-2)=15/5=3
x->7                                                 x->7