>>...two children whose ages differ by 5 years...<<
Let the younger child's age = x
Then the older child's age = x+5
>>...The sum of the squares of their ages is 97...<<
x² + (x+5)² = 97
x² + (x+5)(x+5) = 97
x² + x² + 5x + 5x + 25 = 97
2x² + 10x + 25 = 97
2x² + 10x - 72 = 0
Divide through by 2
x² + 5x - 36 = 0
Factor
(x + 9)(x - 4) = 0
Use the zero-factor principle:
x + 9 = 0; x - 4 = 0
x = -9; x = 4
Ignore the negative answer.
The younger child is 4.
The older child is 5 years older or 9.
>>...The square of the mother’s age can be found by writing
the square of the children’s ages one after the other as a four-digit number...<<
The square of the younger child's age = 4² = 16
The square of the older child's age = 9² = 81
Four-digit number = 1681 so,
The square of the mother's age is 1681.
The mother's age =
= 41
Edwin