here x+3y=13
x=13-3y.....1st equation
-3x+2y=27......2nd euation
now putting the value of x from equation 1st in 2nd we will get
-3(13-3y)+2y=27
-49+9y+2y=27
11y=27+49
y=76÷11
y=6.9
now again putting the value of y in equation 1st we get
x=13-3×6.9
x=13-20.7
x=7.7