book Maths Puzzle Numerical Ability

I have tried to answer this question until I am more confused than ever. Please help.

3(x-1)+4(2x+1)=11x+1

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book Other Question

An island has no currency; it instead has the following exchange rate:

50 bananas = 20 coconuts
30 coconuts = 12 fish
100 fish = 1 hammock

How many bananas equal 1 hammock?

My work cannot figure this problem out.
What are the foci of the ellipse 4x^2 +13y^2 =52?

What is the equation of the ellipse with the center at (0,0), vertex at (0,5) and co -vertex at (-4,0)?