Simplify each of the following: (i) x2−3x+5−12(3x2−5x+7)(ii) [5−3x+2y−(2x−y)]−(3x−7y+9)(iii) 112x2y−94xy2+14xy−114y2x+115yx2+12xy(iv) (13y2−47y+11)−(17y−3+2y2)−(27y−23y2+2)(v) −12a2b2c+13ab2c−14abc2−15cb2a2+16cb2a−17c2ab+18ca2b.