Question

divide 25 into two parts such that 7 times the first part added to 5 times the second part makes 139

Answer 1

Let the first part be x
Let the second part be 25-x
ATQ
7x+5(25-x)=139
7x+125-5x=139
2x+125=139
2x=139-125
2x=14
x=14/2
x=7

THE FIRST PART IS 7
THE SECOND PART IS 18

Answer 2

Let one number be x
x+other number=25
Other number=25-x
7x+5(25-x)=139
7x+125-5x=139
2x=14
x=7
Second number=25-7=18