book Maths Puzzle Numerical Ability

10/ 1/5-2*2

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book Other Question

solve each proportion.

2/7 = x/-42
5/12 = (x+1)/4
(n+8)/-5=(n-3)/-1
(5-w)/(3+w)=13/12

any idea on these?
im absolutely clueless... 5x-9=15-x