Question

Solve each equation by factoring. Check your solutions.

4y^2=81

I have got a general idea how to do, but I get to
(2y{-/+}9) (2y{-/+}9)

Answer 1

\[4y^{2} = 81 \]

Answer 2

yes

Answer 3

step one we need to get by itself how do you think we can do this?

Answer 4

Subtract the 81 and replace with a 0

Answer 5

watch so this actually means 4*y^{2} = 81

or 4 times y^{2}

we need to do the opposite of multiplication which is division.

so we need to first divide both sides by 4

\[\frac{ 4 }{ 4 }y^{2} = \frac{ 81 }{ 4 }\]

\[y^{2} = \frac{ 81 }{ 4 }\]

Answer 6

you could do that also and I'll explain that too.

Answer 7

ok ya i see what I was missing. So after that its y^2= 20.25

Answer 8

Then I get the square root of that and its 4.5

Answer 9

y=4.5

Answer 10

\[\sqrt{y^{2}} = \sqrt{\frac{ 81 }{ 4 }} = \pm~\frac{ 9 }{ 2 }\]

Answer 11

well when you divide by the 4 why not just go ahead and get a decimal? else it could also be 20 1/4

Answer 12

\[20 \frac{ 1 }{ 4 }\]

Answer 13

there we go. I coulnt figure out how you were doing it

Answer 14

I'm not sure how you got that. here is the way that I did this problem, what I was saying above.