Answer:
[tex]35x^{3}+14x^{2} +56x-30x^{2} -12x-48\\35x^{3}-16x^{2} +44x -48\\[/tex]
Step-by-step explanation:
In order to multiply you just have to go term by term, you just first multiply 7x by the whole trinomial:
([tex]5x^{2} +2x+8[/tex])(7x)=[tex]35x^{3}+14x^{2} +56x[/tex]
ANd then you multiply the second term: -6
([tex]5x^{2} +2x+8[/tex])(-6)=[tex]-30x^{2} -12x-48[/tex]
ANd now you just have to add them up together:
[tex]35x^{3}+14x^{2} +56x\\[/tex]
[tex]-30x^{2} -12x-48[/tex]
And this would be equal to:
[tex]35x^{3}-16x^{2} +44x -48[/tex]
