a rational number is a number that can be written in form a/b where a and b are integers (integers are like -5,-4,-3,-2,-1,0,1,2,3,4, etc)
remember that (√a)(√b)=√(ab)
and √(a^2)=a
do each
√3 · √16=√3·√(4^2)=√3·4=4√3 which is irrational
2√9·√4=2√(3^2)·√(2^2)=2(3)·2=6·2=12 which is rational
7√3·√3=7√(3·3)=7√(3^2)=7(3)=21 which is rational
√5·√5=√(5·5)=√(5^2)=5 which is rational
rational expressions:
2√9·√4
7√3·√4
√5·√5
