SOLVE THE EQUATION BY COMPLETING THE SQUARE. X SQUARE +8x-33=0
Still Need Help?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
\[x ^{2}+8x-33\]
OpenStudy (anonymous):
First, take the number infront of x, divide it by 2, and then square it.
OpenStudy (anonymous):
16
OpenStudy (anonymous):
Alright, now add and then subtract it after 8x so you have:
\[x ^{2}+8x+16-16-33\]
OpenStudy (anonymous):
and then factor the \[x ^{2}+8x+16\]
Still Need Help?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
Hint: itll be (x-a)^2 where a equals the number you divided by 2 before you squared it
OpenStudy (anonymous):
so 4
OpenStudy (anonymous):
ok
OpenStudy (anonymous):
So now we have (x+4)^2-16-33
OpenStudy (anonymous):
Move the numbers to the right and you get
(x+4)^2=49
Still Need Help?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
What would you do next to solve for x?
OpenStudy (anonymous):
ok -49 add
OpenStudy (anonymous):
wait -4
OpenStudy (anonymous):
What?
OpenStudy (anonymous):
im lost
Still Need Help?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
If you're solving for x you would take the square root of both sides. it cancels the square out on the left so we have
\[x+4=\pm \sqrt{49}\]
OpenStudy (anonymous):
then it would be7, -1?
OpenStudy (anonymous):
square root 7
OpenStudy (anonymous):
No, now you subtract the 4 from both sides and end up with:
\[x=-4\pm7\]
OpenStudy (anonymous):
Since 7 is the square root of 49.
Still Need Help?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
ok
OpenStudy (anonymous):
Since its plus or minus, you have two separate answers.
x=-4+7 and x=-4-7
or
x=3 and x=-11
OpenStudy (anonymous):
But when you take a square root, you have to go back and check your answers. So plug 3 in for x in the original equation and if its true, that is an answer. Same for -11
OpenStudy (anonymous):
ok that would be an easier way of checking.
OpenStudy (anonymous):
i have another question
Still Need Help?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
Did you check the answers? in this case both 3 and -11 are solutions.
Post your question as a new one and i will look at it