Wednesday, April 17, 2013

Solve for c and d: 3c – d = 30 and 5c – 3d = 10

3c-d=30    (i)                             5c-3d=10  
(ii)


3c-30=d


put the value in
the second
equ


5c-3(3c-30)=10


5c-9c+90=10


4c=80


c=80/4


c=20


now
we have the value of c


we can put this value in any equ to
find the value of d or we can do this the long
way


3c-d=30


3c=30+d


c=30/3+d/3


c=10+d/3


puting
this value in the second
equ


5(10+d/3)-3d=10


50+5d/3-3d=10


50-10=-5d/3+3d


40=-5d/3+9d/3             
(took L.C.M on the right side of equals
to)


40=4d/3


40x3=4d


120=4d


d=30


now
we have the value of d.


we can put the value of c and d in
any equation to check the answer.


(NOTE: This is the
substution method for the solution for simultaneous linear equations. We can also use
the comparison method and many more.)

No comments:

Post a Comment

What accomplishments did Bill Clinton have as president?

Of course, Bill Clinton's presidency will be most clearly remembered for the fact that he was only the second president ever...