tolong donk jawab yang dilingkarin pliss

b) ( 5m - 2n )² - 4 ( 2m + 3n )²
= 25m² - 20mn + 4n² - 4( 4m² + 12mn + 9n²)
= 25m² - 20mn + 4n² - 16m² + 48mn + 36n²
= 9m² + 28mn + 40n²

b) ( 4x+20 / 4x ) ÷ ( x²+3x-10 / x² )
= (4x + 20) ( x²)
---------------------------
( 4x ) ( x² + 3x - 10)

= 4( x + 5) ( x)(x)
-------------------------
( 4)(x)( x + 5)(x - 2)

= x
---------
( x - 2)