AS Maths Problem

4-0.2(y-x) = (2x+3y)/11

(*Thats 2x +3y all divided by 11)

In the form ax+by+c=0 where a,b and c are integers.

(edited 6 years ago)

does 4-0.2(y-x) =11? or have i misread that?
If it is i would rearrange both to equal 0. once they both are equal to 0, then they are equal to each other , then treat as one larger equation

Reply 2

ShadowDemon

Original post by AsianG99

4-0.2(y-x) = (2x+3y)/11

(*Thats 2x +3y all divided by 11)

In the form ax+by+c=0 where a,b and c are integers.

Have you tried expanding the brackets on the left hand side of the equation?

21x-26y +220 =0

Original post by carolyncollis

21x-26y +220 =0

Original post by ShadowDemon

Have you tried expanding the brackets on the left hand side of the equation?

answer in the book is x-26y+220=0
i keep getting the same answer which is wrong
Yeah thats the method i used by expanding the lhs brackets

Reply 5

ShadowDemon

Original post by AsianG99

answer in the book is x-26y+220=0
i keep getting the same answer which is wrong
Yeah thats the method i used by expanding the lhs brackets

What are your workings?

And I think it would help to write the decimals as fractions to lessen the confusion.

Reply 6

carolyncollis

Are you sure the answer is not wrong?

Reply 7

jbiard

Original post by AsianG99

answer in the book is x-26y+220=0
i keep getting the same answer which is wrong
Yeah thats the method i used by expanding the lhs brackets

If you times both sides by fifty five:
220-11(y-x) = 5(2x+3y)

Expand brackets:
220-11y+11x= 10x+15y

Put everything on one side:

x-26y+220=0

Reply 8

AsianG99

Original post by jbiard

If you times both sides by fifty five:
220-11(y-x) = 5(2x+3y)

Expand brackets:
220-11y+11x= 10x+15y

Put everything on one side:

x-26y+220=0

out of all numbers why multiply by 55?

Reply 9

jbiard

Original post by AsianG99

out of all numbers why multiply by 55?

you could write
4-0.2(y-x) = (2x+3y)/11 as
(20-(y-x))/5 = (2x+3y)/11
so you need to times RHS by a multiple of 11 to have whole numbers on the RHS, and need to times LHS by a multiple of 5 to have whole numbers on the LHS. So the lowest common multiple of 5 and 11 is 55.You're just cross multiplying fractions.

So if you times by 55 both sides of the equation will have whole number coefficients so can be put in the form ax+by+c=0