## anonymous one year ago -7x^2=-448 taking the square root and completing the square please show steps

1. anonymous

you do not have to complete the square for this one divide both sides by $$-7$$ then take the square root of both sides don't forget the $$\pm$$

2. max1409
3. pooja195

$\huge~\rm~-448\div-7=?$

4. anonymous

64

5. geerky42

Yep, so now you have $$x^2 = 64$$ Your next step is to take square root of both sides.

6. pooja195

$\huge~\rm~\sqrt{x^2}=\sqrt{64}$

7. anonymous

64 is 8

8. pooja195

good and the square root of X^2 ?

9. anonymous

x

10. pooja195

11. anonymous

8x

12. anonymous

so the equation for it would be like the steps

13. pooja195

Nope remeber the = sign it remains there! $\huge~\rm~x=\pm8$

14. anonymous

what would be the steps

15. pooja195

We just did it ... we need to divide both sides by -7 that way we can isolate the x $\huge~\rm~\frac{ -7x^2=-448 }{ 7 }$ We were left with $\huge~\rm~x^2=64$ we need to solve for x so we need to square root both of those $\huge~\rm~\sqrt{x^2}=\sqrt{64}$

16. pooja195

And when we did this we ended up with... $\huge~\rm~x=\pm8$

17. pooja195

understood ?

18. anonymous

yes i think so if i turned these steps it would be the correct formulas and stuff?

19. pooja195

Can you please rephrase that ?

20. anonymous

i'm suppose to show my work when i turn it in so if i turn these steps in would it be the correct formula?

21. anonymous

can you help me with one more?

22. pooja195

._. this is correct but i expect u to be able to do the next one by yourself if it is like this...i can look over the work :)

23. anonymous

ok well the next one is a little different x^2-10x+22=-2

24. anonymous

do i do the same thing?

25. pooja195

We need to get it into standered for first $\huge~\rm~ax^2+bx+c=0$

26. anonymous

fill it in with the number from the equation?

27. pooja195

x^2-10x+22=-2 we add the -2 to the - $\huge~\rm~22-2=?$

28. anonymous

well -24

29. pooja195

my mistake sorry it would be just 24

30. pooja195

$\huge~\rm~x^2-10x+24=0$

31. pooja195

what numbers multiply to make 24 but adds to make -10

32. anonymous

4 an 6 im not sure

33. pooja195

good -4 and -6 then (x-6) (x-4) set up 2 diffrent equations x-6=0 <---solve for x x-4=0 <----solve for x

34. anonymous

x=6 and x=4

35. anonymous

@pooja195

36. pooja195

yep

37. anonymous

and then?

38. pooja195

thats it

39. anonymous

o so the steps are ?

40. anonymous

i got to go