Answer:
Sam is 12, sam's brother is 19, and sam's mom is 32.
Explanation:
First the equation you need to use is S+7+S+3S-4=63(the variable s represents Sam), you combine the like terms which then equals 5S+3=63, then you use inverse operations. Subtract 3 on both sides, 5S=60, then you divide on both sides which equals S equals 12. Then you just plug in the number, S is Sam which means Sam's 12. Then 12+7 which is 19, Sam's brother. Then 3 times 12 minus 4 is 32. And if you check to make sure, 12+19+32 does equal 63.