Can someone please help me answer these 4 questions?

Farnesene is a sesquiterpene. how many different isomers arising from double-bond isomerizations are possible? g

Write an expression that has three terms and simplifies to 4x - 7. identify the coefficient(s) and constant(s) in your expression

Hich equation can pair with x + 2y = 5 to create an inconsistent system? 2x + 4y = 3 5x + 2y = 3 6x + 12y = 30 3x + 4y = 8