(5a²-8a-1)(2a+1)+(1-10a)(a²-a-3)= 10a³+5a²-16a²-8a-2a-1+a²-a-3-10a³+10a²+30a= 19a-4
19*0,9-4=17,1-4= 13,1
(5a²-8a-1)(2a+1)+(1-10a)(a²-a-3)= 10a³+5a²-16a²-8a-2a-1+a²-a-3-10a³+10a²+30a= 19a-4
19*0,9-4=17,1-4= 13,1