Answer:
Present Time
Let X= Eric's age (4/5)X= Seth's age
Question: What are their ages now?________________________________________________________________________
Past (21 years ago)
X-21 =Eric's age (4/5)X-21=Seth's age
2*[4/5(X-21]=Eric's age
Therefore, X-21= 2*[4/5(X)-21]=Eric's age Substitution
_______________________________________________________________________
X-21= 8/5 X - 42 Solve for "X" by adding 42 to both sides.
X-21+42=(8/5) X
X+21 = (8/5)X Subtract "X" from both sides.
21=(3/5)X Multiply both sides of equation by reciprocal of (3/5), which is 5/3
21*(5/3)= X Finish the problem to find value of "X," which is Eric's age.
Then find 4/5 (X)= Seth's age
210.69 is the answer.
Sorry for not explaining my work, in a bit of a hurry. I had this question back when i was in school.
Hope this helps & good luck. :)
Katework+jeanwork=6
work alone
Katework=-5+Jeanwork
ad 5 to both sides
Katework+5=jeanwork
subsitute 5+katework for jeanwork
5+katework+kateworkwork=6
subtract 5 from both sides
2katework=1
divide both sides by 2
katework=0.5days
equation would be
jeanwork+katework=6 and
katework=jeanwork-5 are the equations
The second option , s = 74 - 33