solving systems of linear equations: advanced

ANSWER IS 33.

SOLVING THE EQ (2)$\Rightarrow$

     2(X+4)+2Y=11+1/2(16+2X)

$\Rightarrow$2X+8+2Y=11+8+X

$\Rightarrow$X+2Y=11 

$\Rightarrow$3X+6Y=33.

SOLVING THE EQ(1)$\Rightarrow$

    X+6Y=R-2X

$\Rightarrow$3X+6Y=R.

THE EQ ARE INFINITE SOLULTION WHEN 

a1/a2=b1/b2=c1/c2

HERE

3X/3X=6Y/6Y=33/R=1

SOLVING FOR R THEN, R=33.