Question

а²-16/5а²+20а при а =0,4

Answer 1

= ( ( a - 4 )( a + 4 )) / ( 5a( a + 4 )) = ( a - 4 ) / 5a
a = 0,4
( 0,4 - 4 ) / ( 5 • 0,4 ) = - 3,6 / 2 = - 1,8

Answer 2

0.16-16/5*0.16+20*0.16
-15.84/0.8+3.2
-15.84/4=-3.96