Maths F4...2

8 (2x+y) ∝ (x-2y)
Let (2x+y)=k(x-2y)
Then (2-k)x=-(2k+1)y => I is trueSince
x+y=[(2k+1)/(k-2)]y+y=[(3k-1)/(k-2)]y
x-y=[(k+3)/(k-2)]y
=>II is trueSimilarly III is true because we can represent x as a function of yANSWER:E11 f(x)=Q(x)(x+4)+R
f(x-4)=[Q(x-4)]x+R=[Q(x-4)](x+4)+R-4Q(x-4)
So Sub x=-4 will give the remainder R-4Q(-8)=f(-8)ANSWER:B12 f(-1)=0. Set x=-1, f(2x+1)=f(-1)=0
So x+1 is a factor of f(2x+1)ANSWER:B