Question

Help..
Solve the system with the addition method:
3(6x+y)=-2
-3(x+5)=3y

Answer 1

Simplify the left side. Change the second equation. Add it to the first.

Answer 2

3(6x+y)=-2--------------------------1)
-3(x+5)=3y--------------------------2)
1) solving 1st equation for y
\[18x+3y=-2\]
\[3y=-2-18x\]
\[y=(-2-18x)/3\]

2) Now put the value of y in the 2nd equation on the place of y

\[x+5=-y\]
\[x+5=(18x+2)/3\]
\[3x+15=18x+2\]
\[15x=13\]
\[x=13/15\]

\[x+5=-y\]
\[13/15+5=-y\]
\[88/15=y\]
\[-88/15=y\]

Answer 3

18x + 3y = -2
-3x -15 = 3y
Or Second Equation can be written as : -3x -3y = 15
Or 3x + 3y = -15

Form 1st equation : 3y = -2 - 18x

Put this in Second Equation :
3x - 2 - 18x = -15
So, -15x = -13

So, x = 13/15 and y = -88/15...

Answer 4

Thank you :) how do i do it with letters instead of numbers /:

Answer 5

-a/4-b/4=1

-a/3+b/6=1