question is:

SOLVE:

4x = 5 = 3(2x+7)

i havent seen one like this yet, what with all the equal signs

can anyone gimme some help as to how to go about this?

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- Jun 3rd 2007, 01:11 PMRyanCoutureHaving Trouble Solving An Algebra Equation
question is:

SOLVE:

4x = 5 = 3(2x+7)

i havent seen one like this yet, what with all the equal signs

can anyone gimme some help as to how to go about this? - Jun 3rd 2007, 01:16 PMJhevon
- Jun 3rd 2007, 01:18 PMRyanCouture
yeah it doesnt make any sense

theres no way to re arrange it or anything? - Jun 3rd 2007, 01:21 PMJhevon
- Jun 3rd 2007, 01:23 PMRyanCouture
it was given to me in a math book:

2. Solve the following equations:

a) 4x=5=3(2x+7)

b) 7x^3+23x+6=0

c) -64z^2 = -121

thats the whole segment - Jun 3rd 2007, 01:31 PMJhevon
i think you made a typo. what hinted that to me is the last equation you typed. you had =64z^2 = -121. it makes no sense to have the = in front of the 64 like that. are you sure it shouldn't be a minus sign, as in a - ?

look at the book again, maybe you should have: 4x - 5 = 3(2x + 7) and -64z^2 = -121 - Jun 3rd 2007, 01:34 PMRyanCouture
lol

yes your right about question c) there it should be -64z

but the first one we were talking about is typed correctly, this math course that im doing (its a mail in one) has had MANY typos so far, so i would be surprised if this is one. - Jun 3rd 2007, 01:40 PMJhevon
- Jun 3rd 2007, 01:44 PMRyanCouture
i think so

do i just expand, then collect like terms

4x-5=3(2x+7)

4x-5=6x+21

4x-6x = 5+21

-2x = 26

x = 26/-2

x = -13

??

what do you think? - Jun 3rd 2007, 02:21 PMRyanCouture
Jhevon ?

your feedback?

also if your still there

how do i go about c)

-64z = -121

thanks - Jun 3rd 2007, 02:34 PMtukeywilliams
you are right for #1.

For $\displaystyle -64z = -121 $ divide both sides by $\displaystyle -64 $.

So: $\displaystyle -\frac{64z}{-64} = -\frac{121}{-64} $

$\displaystyle z = -\frac{121}{-64} \approx 1.89 $

Remember that a negative number divided by a negative number is a positive number. A negative number multiplied by a negative number is a positive number. - Jun 3rd 2007, 02:40 PMRyanCouture
whoops, i made a mistake

the question for c) was:

-64z² = -121

__f__orgot the square

do i go about it the same way?? - Jun 3rd 2007, 02:43 PMtukeywilliams
If the equation is $\displaystyle -64z^{2} = -121 $, then:

$\displaystyle -\frac{64z^{2}}{-64} = -\frac{121}{-64} $

$\displaystyle z^{2} \approx 1.89 $

$\displaystyle z \approx \pm \sqrt{1.89} \approx \pm 1.37 $ - Jun 3rd 2007, 02:45 PMRyanCouture
- Jun 3rd 2007, 02:46 PMRyanCouture
ohh i see, nevermind

so the answer is 1.37?