Question

What is the value of y in the solution to the system of equations? 1x + 1y = 1 2x – 3y = -30​

Answer 1

y=8

Explanation:

`(1)/(3) x + (1)/(4)y= 1\\\\(4x+3y)/(12) =1\\4x+ 3y =12\\y = (12-4x)/(3)`

let's note this as our equation no. (i)

and let 2x-3y = -30 be the equation no. (ii)

Put value of y from (i) into (ii)

`2x -3y = -30\\2x-3((12-4x)/(3) )=-30\\2x -12+4x = -30\\6x = -30+12\\6x= -18\\x = -3`

Now put x = -3 back in equation (i)

`y = (12-4x)/(3)\\y = (12 - 4(-3))/(3)\\y = (12 + 12)/(3) \\y = 8`