Ask your own question, for FREE!
Mathematics 7 Online
OpenStudy (anonymous):

I have five Algebra II questions... Can someone help me? I'm posting them shortly...

OpenStudy (anonymous):

OpenStudy (anonymous):

@phi @amistre64 @AccessDenied

OpenStudy (anonymous):

Solve the equations for x. Identify any extraneous solutions. Show all work.

OpenStudy (anonymous):

If somebody can show me one or two of them, I might be able to get the others by myself...

OpenStudy (ivettef365):

to solve the square root, you need to square both sides and then you have 8x+1 = 25

OpenStudy (ivettef365):

from there can you solve for x

OpenStudy (anonymous):

what's an extraneous solution?

OpenStudy (anonymous):

I got x=3

OpenStudy (ivettef365):

correct

OpenStudy (anonymous):

there aren't any other answers, right?

OpenStudy (ivettef365):

the next problem, first you subtract 5 from both sides, then you square

OpenStudy (anonymous):

x=43?

OpenStudy (ivettef365):

I get the following, you have sqrt(x-7) = 11- 5 sqrt(x-7) = 6

OpenStudy (ivettef365):

now square, then you get x - 7 = 36

OpenStudy (ivettef365):

now solve for x

OpenStudy (anonymous):

x=43

OpenStudy (ivettef365):

correct, you were right all alone

OpenStudy (anonymous):

are there any extraneous solutions?

OpenStudy (amistre64):

if you get more than 1 possible result, and some test false; the false ones are called extras (extranuous)

OpenStudy (anonymous):

oh okay

OpenStudy (anonymous):

For #3, do you start by dividing both sides by -4?

OpenStudy (amistre64):

number 5 has the possibilty of getting some extras since you would have to square an x and solve a quadratic

OpenStudy (amistre64):

yes, divide by -4 first

OpenStudy (amistre64):

i might want to amend my thought of extras :)

OpenStudy (anonymous):

x=16?

OpenStudy (amistre64):

all false solutions are extras; which means that there may be no real solutions

OpenStudy (amistre64):

x=16 is the only thing that might have a chance at working; but the test is false

OpenStudy (anonymous):

so it's the only solution but it's extraneous?

OpenStudy (amistre64):

correct -4(5) = 20, there is no real solution

OpenStudy (anonymous):

but there is one extraneous?

OpenStudy (amistre64):

correct

OpenStudy (anonymous):

Number 4 is x=8?

OpenStudy (amistre64):

correct

OpenStudy (anonymous):

I was just double checking my work and it looks like Number 3 has a solution... What did I do wrong?

OpenStudy (anonymous):

Plugging in 16 for X -4sqrt(16+9)=20 sqrt(16+9)=-5 16+9=25 25=25

OpenStudy (anonymous):

@amistre64

OpenStudy (anonymous):

I don't understand number 5 at all

OpenStudy (ivettef365):

first subtract the 4 and you get the following sqrt(x+2) = x - 4

OpenStudy (ivettef365):

then when you square, you have x+ 2 = (x-4)^2

OpenStudy (ivettef365):

then you solve as follows; x+2 = (x-4)(x-4) x+2 = x^2-4x-4x+16 x+2 = x^2-8x+16

OpenStudy (ivettef365):

can you take it from there

OpenStudy (anonymous):

@ivettef365 what do you do with the x^2?

OpenStudy (ivettef365):

ok, this is what you do x+2-x-2 = x^2-8x+16-x-2 0 = x^2 -9x+14

OpenStudy (ivettef365):

now x^2-9x+14 (x-7)(x-2) = 0

OpenStudy (ivettef365):

so now to find value of x, x-7 = 0 x = 7 and x-2 = 0 x = 2

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!