You can put this solution on YOUR website! Let Gugu's age be n + 7
Let her sister's age be n
Therefore:
n + n + 7 = 33
Combine like terms:
n + n = 2n
2n + 7 = 33
Subtract 7 from each side of the equation
2n + 7 - 7 = 33 - 7
Combine like terms:
7 - 7 = 0
33 - 7 = 26
2n = 26
Divide each side by 2
2n/2 = 26/2
n = 13
n + 7 = 13 + 7 = 20