Answer:
Kim's age is twice of that of her sister. We'll let k2 = Kim and k = Kim's sister.
So, k2. When you add Kim's age to her sister age you get 30.
Because Kim is twice the age of her sister k2. And because it said 'add' then we put a + sign. k2 + s = 30. Now let's solve it.
k2 + k = 30 < Given
3k = 30 < Combine like terms
k = 10 < Divide both sides by 3
We know Kim's sister is 10 y/o but what about Kim herself? Earlier we assigned Kim to k2. Substitute 10 for k and you get 10(2) = 20
Kim's sister is 10 y/o and Kim is 20 y/o
Step-by-step explanation: