EJERCICIOS 09 - 24 "LA RECTA"

09) HALLAR A + B SI:

l1 :ax-by=4

l2 :bx+ay=33

l1∩l2 -> p(3;2)

3a-2b=4

2a+3b=33

__________
9a-6b=12

4a+6b=66

_________

13a=78

a=6

=> 2(6)+3b=33

3b=21
b=7

* a+ b =13*

10) HALLAR K SI:

l1: kx+(k+1)y+2=0

l2: 3k-2y=4

l1┴l2 => m1.m2=-1

(-k/k+1)(3/2)=-1

3k/2k+2=1

3k=2k+2

k=2

12) HALLAR LA ECUACION DE LA RECTA:

l1: y=3x+5 ------> m1=3

P(4;-3)

l // l1 m=m1=3

y-y1=m(x-x1)

y+3=3(x-4)

y+3=3x-12

y=3x-15

13) hallar la ecuacion:

A(-3;-1) ^ B(4;3)

i) m=-1-3/-3-4=-4/7=4/7

y-y1=m(x-x1)

y-3=4/7(x-4)

7y-21=4x-16

4x-7y+5=0

15)HALLAR X+Y:

l1:3x+2y-16=0

l2:7x-5y+11=0

3x+2y=16

7x-5y=-11

___________

15x+10y=80

14x-10y=-22

____________

29x=58

x=2

=> 9(2)+2y=16

2y=10

y=5

* x+y=2+5=7*

16) HALLAR "W" SI:

l1┴l2 =>m1.m2=-1

l1:(k+2)x+2y-3=0 ------- m1= 5

l2:3x+(3-k)y+2=0 ------- m2= -1/5

m1.m2=-1

(k+2/2).(3/3-k)=-1

3k+6/6-2k=-1

3k+6=-6+2k

k=-12

*w=2m1+5m2

=2(5)+5(-1/5)

= 10-1

* w=9*

19) HALLAR X:

l1┴l2 => m1.m2=-1

(-6-2/-4-3).(-6-1/x+7)=-1

(-8/-7).(-7/x+7)=-1

8x=x+7

x=1

24)HALLAR EL AREA DEL TRIANGULO FORMADO POR "L":

i) tabular : x 0 -4

y -5 0

l:5x+4y+20=0

*S=5.4/2=10u*

juan carlos alava tacilla