## anonymous 4 years ago -4-7/4x=10 Solve the following equation. Please show all work! Have done just want a second opinion

1. phi

what did you get?

2. anonymous

x=14

3. phi

is the problem $-4 - \frac{7}{4x} = 10$

4. phi

if so, $-4 - \frac{7}{4\cdot 14}=10$ which does not work. if the problem is $-4 - \frac{7}{4}x=10$ then with x=14 $-4 - \frac{7}{4}14=10$ which also does not work.

5. anonymous

I added 4 to both sides

6. phi

that is a good start. but which problem is it (see above)?

7. anonymous

I subtracted the ricp from it too, I guess I just need to start over again

8. phi

Let's do -4 - (7/4)x = 10 (the x is up top) then add 4 to both sides -(7/4)x= 14 this is what you got, right? to get rid of the -7/4 *multiply* by the reciprocal on both sides of the equation

9. anonymous

yes

10. phi

can you do $\frac{-4}{7}\cdot \frac{-7}{4}x= 10\cdot \frac{-4}{7}$

11. anonymous

cant cancel can you since the 4 and 7 are oposit of each other

12. anonymous

-4/7*-7/4 =0

13. phi

You can cancel (that is why we are doing it). the order of multiplication does not matter 2*3= 3*2 so $\frac{-4}{7}\cdot\frac{-7}{4} =\frac{-7}{7}\cdot\frac{-4}{4} = -1\cdot -1= 1$

14. anonymous

x=-4/70?

15. anonymous

just makes it x

16. phi

close, but think of the 10* -4/7 as $\frac{10}{1}\cdot \frac{-4}{7}$ multiply top times top and bottom times bottom

17. anonymous

nice

18. anonymous

-4/70

19. phi

Let's back up: -4 - (7/4)x = 10 then add 4 to both sides -(7/4)x = 14 x = 14 * -4/7 can you finish this?

20. anonymous

56/7

21. phi

what happen to the minus sign?

22. anonymous

forgot to put it in

23. anonymous

-56/7

24. phi

OK, let's check your answer x= -56/7 you start with -4 - (7/4)x = 10 if x is -56/7 then the left-hand side is -4 - (7/4)*(-56/7) can you do this?

25. phi

before you forget notice that it is minus times minus so -7/4 * -56/7 is + (cancel the minus signs) also, you can cancel the 7's

26. anonymous

14

27. phi

keep going, you are doing -4 - (7/4)*(-56/7)

28. phi

you found -7/4 * -56/7 = +14 so now -4 + 14 =

29. anonymous

-4(14)=56

30. anonymous

-56

31. phi

look at it more carefully we are adding

32. anonymous

18

33. phi

-4 - (7/4)*(-56/7) --> -4 + 14

34. phi

4+14= 18 -4 + 14 = ?

35. phi

when you add negative numbers, it's like subtraction.

36. anonymous

-10?

37. phi

-4 + 14 is the same problem as 14 - 4

38. phi

39. anonymous

Thank you it might I hope so thanks for all of your help

40. phi

you will get +10 which matches the original -4 - (7/4)x = 10 you figured out that when x= -56/7 that the equation turns into 10 = 10 which means you got the right answer.

41. anonymous

With lots of help from you thanks

42. phi

If the video helps and is not too boring, then search for the videos on solving equations (use his search window). If something does not make sense, search for a video that explains it, because he explains *everything*

43. anonymous

Thank you I will look at the links wheather they are boring or not I need the info