Question

Decide whether given sets are equal sets. Give reasons: A {x/x = 3n,n €N, 0<x<15}
B = { y/ y is a number that gives remainder zero when divided by 3, 1≤ ≤ 15}
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Answer 1

Answer:

(i) A={2,3}

B={x:x is a solution of x

2

+5x+6=0}

x

2

+5x+6=0

x(x+3)+2(x+3)=0

(x+2)(x+3)=0

x=−2 or x=−3

∴B={−2,−3}

∴A



=B

(ii) A={x:x is a letter in the word FOLLOW}={F,O,L,W}

B={y:y is a letter in the word WOLF}={W,O,L,F}

The order in which the elements of a set are listed is not significant.

∴A=B

Step-by-step explanation:

(i) A={2,3}

B={x:x is a solution of x

2

+5x+6=0}

x

2

+5x+6=0

x(x+3)+2(x+3)=0

(x+2)(x+3)=0

x=−2 or x=−3

∴B={−2,−3}

∴A



=B

(ii) A={x:x is a letter in the word FOLLOW}={F,O,L,W}

B={y:y is a letter in the word WOLF}={W,O,L,F}

The order in which the elements of a set are listed is not significant.

∴A=B