How do you simplify 225x18y22?

2 Answers
Dec 11, 2016

15x9y11

Explanation:

Recall : x=x12,andx2=(x2)12=x212=x,

225x18y22=1515x18y22=(152x18y22)12
=15212x1812y2212
=15x9y11

Dec 11, 2016

225x18y22=15x9y11

Explanation:

Note that:

225x18y22=152(x9)2(y11)2=(15x9y11)2

So 15x9y11 is a square root of 225x18y22.

We also find:

(15x9y11)2=225x18y22

So 15x9y11 is also a square root of 225x18y22.

Note that if a0 then a denotes the non-negative square root.

So if, for example, x<0 and y>0 then 15x9y11<0 would be the wrong square root.

We can express that we want the non-negative square root by taking the modulus:

225x18y22=15x9y11