Question 239741
Write an equation for each statement
:
Together, Saturn, Jupiter, and Uranus have a total of 113 known satellites (moons). 
S + J + U = 113
:
"Jupiter has 30 more satellites than Saturn,"
J = S + 30

" Uranus has 10 fewer satellites than Saturn."
U = S - 10
:
 How many known satellites does Saturn have? 
:
Using the 1st equation: S + J + U = 113, we can replace J with (S+30) and U with (S-10)
S + (S+30) + (S-10) = 113
Combine like terms
S + S + S + 30 - 10 = 113
3S + 20 = 113
3S = 113 - 20
3S = 93
S = {{{93/3}}}
S = 31 moons on Saturn
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You should check the solution by substituting for J and U and adding them up