1. Rational/The sum of two rationals is always rational
2. Irrational/ the sum of a rational and an irrational is always irrational
3. Irrational/The product of a nonzero rational and an irrational is always irrational
4. Rational/The product of two rationals is always rational
Pretty much all the irrational numbers are the ones with radical signs over them and the rational numbers are the fractions and whole numbers. Once you identify the two numbers to be rational or irrational, you can then find your answer within the second part of the answers.
Answer:
2/3
Step-by-step explanation:
I assume the 2 after the j is a square. So, we bring the 21 to the other side by subtracting it from both sides, getting 144j^2=64. Now we divide to get 64/144 = j^2. Make sure NOT to simplify it, it's perfect right now. The square root of that is
, or 8/12, which we can now simplify to 2/3. Hope this helps!