Question 297903
<b>Variables Used</b><ul>
	<li>S = Sarah</li>
	<li>c = cousin</li></ul>
What do we know? We know that:
S = 5c
S + 4 = 3(c + 4) <br>
Substitute "5c" for S in the second equation:
5c + 4 = 3(c + 4) <br>
Distribute:
5c + 4 = 3c + 12 <br>
Subtract 3c from each side:
5c -3c + 4 =  12 <br>
Subtract 4 from each side:
2c =  8 <br>
Divide both sides by 2 and find that 
c = 4<br>
Substitute "4" for "c" in the 1st equation:
S = 5(4) and we find that 
Sarah is 20 years old and her cousin is 4 years old 
 & bob's your uncle!