Can anyone answer this algebra question?

Question

If 6 is added to a number then subtracted from the same number, the product of the sum and the difference is 189. What is the number?

-+ 7, -+ 8.2, -+ 12.4, or -+ 15

Answer 1

(x+6)(x-6)=189

x^2-36=189

x^2 = 225

x = -+15

-+15 is the answer

Answer 2

Let x = the number

(x + 6) (x - 6) = 189

x² - 36 = 189

x² = 225

x = ±15

Answer 3

In other words,

(x + 6)(x - 6) = 189?

x^2 - 36 = 189

x^2 = 225

x = ±15

Check:

9 * 21 = 189? yes

(likewise, -21 * -9 = 189)

Answer 4

You mean (a+6)(a-6)=189,

then a^2 - 36=189,a^2=225,so a=+15 and a=-15,two anwers are correct

in algebra.

Answer 5

x+6 (x-6) = 189

x^2 - 36 = 189

x^2 = 225

x= 15 or x = -15

same process for all the rest

Here's one with decimals, just as an example

(x-8.2)(x+8.2)=189

x^2 - 67.24 = 189

x^2 = 256.24

x= sq rt 256.24 =~16 or ~ -16