if 9 a - b = 10 b + 60 = - 12 b - 2 a , what is the value of 11 a + 11 b ?
"( i ) 9 a - 11 b = 60 ( ii ) 2 a + 22 b = - 60 adding ( i ) and ( ii ) : 11 a + 11 b = 0 the answer is c ."
multiply(negate(multiply(divide(60, 2), 2)), 11)