4x+6y=1/8+3x+7y=1/10

3 answers

Poorly written.
I bet you mean:
4x+6y=1/8
3x+7y=1/10

multiply the first by 3 ----> 12x + 18y = 3/8
multiply the 2nd by 4 ----> 12x + 28y = 2/5
subtract the new first from the new 2nd
10 y = 2/5 - 3/8 = 1/40
y = 1/400

sub into original first equation:
4x+6(1/400)=1/8 <---- multiply everybody by 400
1600x + 6 = 50
x = 44/1600 = 11/400
4 x + 6 y = 1 / 8 + 3 x + 7 y = 1 / 10

mean:

4 x + 6 y = 1 / 10

1 / 8 + 3 x + 7 y = 1 / 10

Rewrite second equation:

1 / 8 + 3 x + 7 y = 1 / 10

Subtract 1 / 8 to both sides

1 / 8 + 3 x + 7 y - 1 / 8 = 1 / 10 - 1 / 8

3 x + 7 y = 1 / 10 - 1 / 8

3 x + 7 y = 4 ∙ 1 / 4 ∙ 10 - 5 ∙ 1 / 5 ∙ 8

3 x + 7 y = 4 / 40 - 5 / 40

3 x + 7 y = - 1 / 40

Now you must solve system of two equations:

4 x + 6 y = 1 / 10

3 x + 7 y = - 1 / 40

Try that.

The solutions are:

x = 17 / 200 , y = - 1 / 25
Reiny may be right.

Really what does 4 x + 6 y = 1 / 8 + 3 x + 7 y = 1 / 10 mean?