Question

Can someone check my answers please? :)

1. Solve the equation using square roots.
x^2-81=0

*-√9,√9 <<<
*-81,81
*-9,9
*no real number solutions

2. 3x^2-147=0

*-49,49
*-7,7
*-√7,√7 <<<
*no real number solutions

3. The area of a playground is 20 square yards. The length of the playground is 5 times longer than its width. Find the length and width of the playground.

*length=1 yd, width=20 yd
*length=2 yd, width=10 yd
*length=10 yd, width=2 yd
*length=20 yd, width=1 yd

For this one I was kind of caught between B and D. Any help is appreciated!

Answer 1

\(x^2 = 81 \\ x^2= 9^2
\\ x = \pm 9\)

and not square root of 9.
same error for 2nd

Answer 2

Thank you so much! @hartnn

Answer 3

still need help for 3rd?

Answer 4

If you could, that'd be great :)

Answer 5

let the width be x
length = 5x

Area = length*width = 5x^2 = 20

get x from here :)

Answer 6

Thank you!!

Answer 7

np,
bdw what did you get for 3rd?

Answer 8

just to cross-check...

Answer 9

I got 2,-2 ?

Answer 10

we discard -2 as width can't be negative

Answer 11

so width = 2
length = 10 :)

Answer 12

You're a life saver, thank you so much :)

Answer 13

welcome ^_^