développer et réduire les expressions (4a+3)(3a+5) (-3a+2)(5a-4) (5b-2)(-3b+2) (5a-3b)(4b+3a)

(4a+3)(3a+5)
12a²+20a+9a+15
12a²+29a+15

(-3a+2)(5a-4)
-15a²+12a+10a-8
-15a²+22a-8

(5b-2)(-3b+2)
-15b²+10b+6b-4
-15b²+16b-4

(5a-3b)(4b+3a)
20ab+15a²-12b²-9ab
15a²-12b²+11ab

(4a+3)(3a+5)
=12a²+29a+15

(-3a+2)(5a-4)
=-15a²+22a-8

(5b-2)(-3b+2)
=-15b²+4b-4

(5a-3b)(4b+3a)
=15a²-12b²+11ab