lucwex Group Title 10. Plans for a bridge are drawn on a coordinate grid. One girder of the bridge lies on the line y = –9x – 9. A perpendicular brace passes through the point (–1, 7). Write an equation of the line that contains the brace. y – 1 = –1/9(x + 7) x – 7 = –9(y + 1) y – 7 = 1/9(x + 1) y – 7 = –9(x + 1) one year ago one year ago

1. NickR

ok so what we are going to do is find the inverse equation start by using the rule The gradient of the new line is -(1/grad of old line).

2. lucwex

what do you mean -(1/grad of old line). im a little confused pal

3. NickR

4. lucwex

–1/9=slope right

5. NickR

-(1/-9)

6. NickR

simplify

7. lucwex

so its a?

8. NickR

slope=1/9

9. lucwex

ooo C

10. NickR

so now take that and make a new equation y=(1/9)x+b

11. lucwex

y – 7 = 1/9(x + 1) thanks pal

12. lucwex

Write the equation for the horizontal line that contains point G(–8, 8). could you give me another hand please

13. NickR

np hope i helped

14. NickR

ya sure 1 sec

15. lucwex

alright cool thanks man youre really helping

16. NickR

ok whats the next problem?

17. lucwex

Write the equation for the horizontal line that contains point G(–8, 8).

18. NickR

so if its a horizontal line the only point we need to worry about is y correct

19. lucwex

yessir

20. NickR

21. NickR

we dont need to worry about the slope because it is 0

22. lucwex

thanks man could you help me write the equation please?

23. NickR

thats it y=8

24. lucwex

oh haha thanks man

25. NickR

np you understand y right?

26. lucwex

ya because its just a straight line. theres no x

27. NickR

ok let me know if you need any more help

28. lucwex

alright will do thanks again bud

29. NickR

np