Matematicas

26.-
limx→2x+7-3x-2=2+7-32-2=3-32-2=00
x+7-3x-2×x+7+3x+7+3=(x+7)2-(3)2x-2x+7+3=x+7-9x-2x+7+3=x-2x-2x+7+3
=1x+7+3
limx→21 x+7+3=12+7+3=19+3=13+3=16

27.-limx→1x+3-2x2-1=1+3-21-1=2-21-1=00
x+3-2x2-1×x+3+2x+3+2=(x+3)2-(2)2x2-1 (x+3+2)=x+3-4x2-1 (x+3+2)=x-1x2-1(1+3+2)
=1x+1(1+3+2)
limx→11 x+1(x+3+2)=11+1(1+3+2)=12(4)=1828.-
limx→09+x-3x2+2x=9+0-302-2(0)=3-30-0=00
9+x-3x2+2x×9+x+39+x+3=(9+x)2-(3)2(x2+2x) (9+x+3)=9+x-9xx+2(9+x+3)
limx→01x+2(9+x+3)=10+2(9+0+3)=12(6)=112

29.-limx→09+x-3x2+2x=9+0-302-2(0)=3-30-0=00
1+x-14+x-2×1+x+11+x+1×4+x+24+x+2=[(1+x)2-(1)2](4+x-2)[(4+x)2-(2)2](1+x+1)=1+x-1(4+x-2)4+x-4-(2)2=x(4+x-2)x-4limx→0x(4+x-2)x-4=0(4+0-2)0-4=0(2-2)0-4=0-4=0

30.-
limx→12-x-12-x+3=2-1-12-1+3=1-12-2=002-x-12-x+3×2-x+12-x+1×2+x+32+x+3=[(2-x)2-1)2(2+x+3)[(2)2-(x+3)2](2-x+1)=(2-x-1)(2+x+3)(4-x+3)(2-x+1)=1-x(2+x+3)(7-x)(2-x+1)
limx→11-x(2+x+3)(7-x)(2-x+1)=1-1(2+1+3)(7-1)(2-1+1)=06(2)=012=0

31.-
3x-4para x≠2
f(x) 5 para x=2 C=2

limx→23x-4=32-4=6-4=2
limx→25=5

32.-x2-3x+1 para x≠1
f(x) 7 para x=1 C=1limx→1x2-3x+1=(1)2-31+1=1-3+1=-1
limx→17=7

33.-
x2-4x-2 para x≠2
f(x) 3para x=2 C=2

limx→2(2)2-42-2=00
x2-4x-2=x+2x-2x-2=x+2
limx→2(x+2)=2+2=4
limx→23=3