102 x a + 98 x b + 52 x a + 57 x b +a
= (102 x a + 52 x a +a) + (98 x b + 57 x b)
= (102+52+1) x a + (98+57) x b
= 155 x a + 155 x b
= 155 x (a+b)
=155 x 13
=2015
[tex]102 * a + 98 * b + 52 * a + 57 * b +a = (102 * a + 52 * a +a) + (98 * b + 57 * b) = (102+52+1) * a + (98+57) * b = 155 * a + 155 * b = 155 * (a+b) ( Thay a & b ) = 155 * 13 =2015[/tex]