Ask your own question, for FREE!
Mathematics 18 Online
OpenStudy (anonymous):

6a(4+6z)= 1+9

zepdrix (zepdrix):

Eyyy, sup? We solving for z or something?

zepdrix (zepdrix):

Need some directions :3

OpenStudy (matlee):

its b

OpenStudy (anonymous):

yes please :) @zepdrix

zepdrix (zepdrix):

\[\Large\rm 6a(4+6z)=1+9\]Add the 1 and 9, ya?\[\Large\rm 6a(4+6z)=10\]We COULD distribute the 6a to each term in the brackets, but that creates more work for us. Notice that the 6a is `multiplying` the brackets.

zepdrix (zepdrix):

Let's do the inverse, let's divide 6a to the other side k?

OpenStudy (anonymous):

ok

OpenStudy (anonymous):

so you would et 1.67a right??

OpenStudy (anonymous):

on the right side

OpenStudy (anonymous):

haha what do you mean :P @Nnesha

zepdrix (zepdrix):

\[\Large\rm \frac{\cancel{6a}(4+6z)}{\cancel{6a}}=\frac{10}{6a}\]\[\Large\rm (4+6z)=\frac{10}{6a}\]No no careful! :) Notice that the a is stuck in the bottom. We can't call it 1.67a. Maybe we just leave it like this, so there is no confusion. Now we have nothing being applied to the brackets, we can just ignore them.\[\Large\rm 4+6z=\frac{10}{6a}\]

zepdrix (zepdrix):

And continue to isolate the z :O It has a 4 being added ya? How we undo that?

OpenStudy (anonymous):

we subtract 4?

zepdrix (zepdrix):

\[\Large\rm 6z=\frac{10}{6a}-4\]Mmm k good, just gotta undo that last multiplication step now :)

OpenStudy (anonymous):

ok so your talking about the 6z right??

zepdrix (zepdrix):

Yes, the 6 is multiplying z, we want to undo that in order to get our z alone.

OpenStudy (anonymous):

ok so we divide 6to both sides?

zepdrix (zepdrix):

Yes. Since we already have a fraction on the right side, it's going to look a little weird. Do you understand how to divide that first fraction by 6?

OpenStudy (anonymous):

not really haha

zepdrix (zepdrix):

Umm ok, maybe here is an easier way to think of it. When you see a fraction like this:\(\Large\rm \frac{1}{5}\) try to get in the habit of thinking of that as a division operation. Yes, we're multiplying by 1/5, but what we're really doing is dividing by 5, because there is a 5 in the bottom. So another sneaky way we can divide both sides by 6 is to multiply both sides by 1/6.

zepdrix (zepdrix):

\[\Large\rm \frac{1}{\cancel6}\cdot \cancel6z=\left(\frac{10}{6a}-4\right)\frac{1}{6}\]

OpenStudy (anonymous):

oh ok i see what youu did :)

OpenStudy (anonymous):

so thats the final answer right??

zepdrix (zepdrix):

We'll give that 1/6 to each term in the brackets,\[\Large\rm z=\frac{10}{6a}\cdot\frac{1}{6}-4\cdot\frac{1}{6}\]You remember how to multiply fractions? :o

OpenStudy (anonymous):

i think so... you would multiply -4 to the top and bottom?? or no haha :P

zepdrix (zepdrix):

-4 is the same as -4/1. With fraction multiplication we do `top with top`, `bottom with bottom`, ya? :) So it looks like ONLY the top will get a -4.

OpenStudy (anonymous):

oh ok :) i was close... :P

zepdrix (zepdrix):

\[\Large\rm z=\frac{10}{6a}\cdot\frac{1}{6}-\frac{4}{6}\]And we do same with the first term, multiply top with top, bottom with bottom, giving us,\[\Large\rm z=\frac{10\cdot1}{6\cdot6a}-\frac{4}{6}\] \[\Large\rm z=\frac{10}{36a}-\frac{4}{6}\]

zepdrix (zepdrix):

And then I guess the only last little step you might want to do is to simplify the fractions :o We have a bunch of even numbers, so they should simplify a bit.

OpenStudy (anonymous):

So it would be z = 5/18 -2/3 right??

zepdrix (zepdrix):

yay good job \c:/

zepdrix (zepdrix):

Woops, `a` still in the bottom of the first fraction*

OpenStudy (anonymous):

so do we have to do something about that??

zepdrix (zepdrix):

Nah, that's just how the problem worked out :)\[\Large\rm z=\frac{5}{18a}-\frac{2}{3}\]

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!