Respuesta :

If both Bob and Fred make $20 less a week than twice John's weekly salary, then

[tex]B+F+20 = 2*J[/tex],

where B, F, and J are Bob's, Fred's, and John's salaries, respectively.

We want to find F, Fred's salary. Plugging in Bob's and John's salaries, we obtain

[tex]140+F+20 = 2*110[/tex]

[tex]F+160 = 220[/tex]

[tex]F = 60[/tex]

So Fred makes $60 a week.

Answer:

Fred makes $60/week.

Step-by-step explanation:

Fred makes f dollars per week, john j dollars and bob b dollars.

Then b = $140/week; j = $110/week; and b + f = 2j - 20.

Substitute $140/week for b in this equation; also substitute $110/week for j.  Then:  

    $140/week + f = 2($110) - $20.  There's only one variable here, f, so we're ready to solve for f:

    $140/week + f = $220/week - $20/week,   or:

     $140/week + f = $200/week

Subtract $140 from both sides, obtaining:

f = $60

Fred makes $60/week.