Where is the problem at? give me the url
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Answer:
First it says that you have to multiply the number x times 2, this will give you 2x as a result. Next you have to build your equation which is 2x=10, when you have an equation like this, you divide the result with the number before x (x=10÷2) your result will be x=5. Now you have to square the result (which is x) to get y, when squaring a number you have to multiply it by itself (depending of how many times it's asking to do so when there's a small number at the upper right corner of your number, that's how many times you multiply it) so if you have to square 5, it should be 5×5 which gives you the result of y being 25.
Y^2-9^2
(y-9)(y+9)
To see if its right:
y*y+y*9-9*y-9*9
y^2+9y-9y-81
y^2-9^2