1.5x5/8+7x5/8
=5/8x(5+7)
=12x5/8
=15/2
2.3/4x5/7-3/4x1/7
= 3/4x(5/7-1/7)
=3/4x4/7
=3/7
3.7/8x3/17x5/7
=7/8x5/7x3/17
=5/8x3/17
=15/136
4.11/19x2/7x5/11
=11/19x5/11x2/7
=5/19x2/7
=10/133