Answer:
x = 4
b = 7
n = 40
I hope this helps!!!
Explanation:
1) 12x-17 = 6x+7
+17 +17
*do this because you want to get all of the variables to one side and all of the constants to one side*
12x = 6x + 24
-6x -6x
6x = 24
*divide by 6 to get x alone, so you 24/6 = 4*
x = 4
2) -8b+1 = -5(b+4)
*must multiply -5 by everything in the parenthesises*
-8b+1 = -5b-20
-1 -1
-8b= -5b-21
+5b +5b
-3b = -21
b = 7
3) 350+10(n-7) = 630+2(n-15)
350+10n-70 = 630+2n-30
*combine like terms on both sides of the equation*
280+10n = 600+2n
-280 -280
10n = 320+2n
-2n -2n
8n = 320
n = 40