Given
3 times the sum of a number and 4 is 8 less than half the number.
Find
an equation for the number
the number
Solution
Translating the given description to math symbols, we have
... 3(n +4) = -8 + n/2 . . . . . the equation
Eliminate parentheses
... 3n + 12 = -8 + n/2
... 3n = -20 + n/2 . . . . . . . subtract 12
... 2.5n = -20 . . . . . . . . . . subtract n/2
... n = -20/2.5 = -8 . . . . . divide by the coefficient of n
The number is -8.
_____
Check
3(-8+4) = -8 + (-8)/2
3(-4) = -8 -4
-12 = -12 . . . . . . . . . . . the answer works in the original problem