How do u name this orgainc compound?

Question

Ch3-C (double bond) CH-CH-C=CH-CH3
CH3

Answer 1

CH3-CH=CH-CH-CH=CH-CH3

Longest chain is 7 carbons, thus sept-
2 double bonds -ene
double bonds at C2 and C5, thus 2,5-heptadiene

Answer 2

I'm going to assume you meant
(CH3)2-C=CH-CH2-CH=CH-CH3.

The difference is in the carbon between the double bonds; it should be a CH2.

The name is 2-methyl-2,5-heptadiene.

Answer 3

2,5 Heptadiene