Answer:
Jack is 8 years old
Explanation:
X2 +5=21
21-5=16%2=8
Jack is 8
j= jacks age
2j+5 =21
This is the equation from Twice jacks age plus five is 21
We want to isolate j
Subtract 5 from each side
2j+5-5 = 21-5
2j = 16
Divide by 2
2j/2 =16/2
j =8
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