Question 462753
"John is 13 years old. He is 3 years older than twice his sister Mary's age. How old is john?"


John is 13.....it's in the first sentence.


x = Mary's age
2x + 3 = John's age


2x + 3 = 13 {John's age is 13, he is 3 yrs older than twice Mary's age}
2x = 10 {subtracted 3 from both sides}
x = 5 {divided both sides by 2}


John is 13 and Mary is 5
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