1. ( 4327- x )-3217 =609
4327-x=609+3217
x=4327-3826
x=501
2. 500 - ( x +138 ) + 59 = 70
559-x-138=70
421-x=70
x=421-70
x=351
3. ( 78 - x ) + 34 =2030 - 45
78-x=1985-34
78-x=1951
x=78-1951
x=-1873
4.a +b + c = 6 259
a+ b = 3 456 c=6259-3456=2803
c =a + 1 143 a=2803-1143=1660
b= 3456-1660=1796