tolong dijawab ya kak 5 dan 6

5) x = ( 42 × 6 ) + ( 3 × 8 ) / ( 42 + 3 )
x = 252 + 24 / 45
x = 276 / 45
x = 6,1 ( B )

6) misal byk siswa semula = a
51 = ( a × 50 ) + 70 / ( a + 1 )
51 ( a + 1 ) = 50a + 70
51a + 51 = 50a + 70
51a - 50a = 70 - 51
a = 19 ( A )