Given A={x:11x−5>7x+3,xϵR} and B={x:18x−9≥15+12x,xϵR}.
Find the range of set A∩B.
Let's take first inequation:
11x−5>7x+3
Rule: If a term of an inequation is transferred from one side to the other side of the inequation, the sign of the term gets changed. Let's apply this rule in the above inequation.
⇒11x−7x>5+3
⇒4x>8
⇒x>2
∴A={x:x>2,xϵR} ...(i)
Let's take second inequation:
18x−9≥15+12x
Rule: If a term of an inequation is transferred from one side to the other side of the inequation, the sign of the term gets changed. Let's apply this rule in the above inequation.
⇒18x−12x≥15+9
⇒18x−12x≥24
⇒6x≥24
⇒x≥4
∴B={x:x≥4,xϵR} ...(ii)
The range of set A∩B={x:x≥4,xϵR}