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# Core surds help plz :-)

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1. Hi, In a textbook it says:
" Show that if neither x nor y is equal to 0, then root x and y is never equal to root x and root y."
I dont understand this question at all, i'm in year 12. someone please simplify this question and help me with this please!!
Thankyou
2. (Original post by Chelsea12345)
Hi, In a textbook it says:
" Show that if neither x nor y is equal to 0, then root x and y is never equal to root x and root y."
I dont understand this question at all, i'm in year 12. someone please simplify this question and help me with this please!!
Thankyou
That can't be what it says exactly - what does it say exactly? Is there another part of the question?
By and do you mean plus?
3. (Original post by Chelsea12345)
Hi, In a textbook it says:
" Show that if neither x nor y is equal to 0, then root x and y is never equal to root x and root y."
I dont understand this question at all, i'm in year 12. someone please simplify this question and help me with this please!!
Thankyou
Huh?

If neither root x nor root y is equal to 0, then root of xy is not 0.
4. (Original post by ValerieKR)
That can't be what it says exactly - what does it say exactly? Is there another part of the question?
" Show that If neither x nor y is equal to 0 , then √x+y is never equal to √x + √y."
5. (Original post by Chelsea12345)
" Show that If neither x nor y is equal to 0 , then √x+y is never equal to √x + √y."
square both of them
the first one you get
x+y
the second one you get x+y+2root(xy)

subtract them to find the difference
2root(xy)
they are equal when this = 0
2root(xy)=0
root(xy)=0
xy=0
x or y = 0

therefore if neither x nor y is 0 the difference cannot be 0 and they cannot be equal

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