Help me with this Maths problem :'(?

I dident understand the first question perhaps write it again? :)

For q2: since it sais SUM we use the rule Sn=n/2(2a+(n-1)d) were n is the number of terms, Sn is the sum of those terms, a is the first term and d is the common difference. Lats denote the first term(a) by x and the common difference(d) by 2x since its twice the first term(a). Since we have the sum of the first 10 terms we can conclude that N=10 and Sn or S10 is 25. So we have:

25=10/2(2x+(10-1)2x)

25=5(2x+(9*2x))

25=5(2x+18x)

25=5(20x)

25=100x

X=25/100

X=1/4

So x is 1/4 or 0.25 which is the first term and since the common difference is twice this it will be 1/2 or 0.5.

Now to find the 10th term we use the rule Un=a+(n-1)d were Un is the term u want to find not the SUM. In this case it will be 10 so n=10 a is 0.25 from last equation and d is 0.5 we get:

U10=0.25+(10-1)0.5

U10=0.25+(9*0.5)

U10=0.25+4.5

U10=4.75

The 10th term is 4.75.

Looks hard but once u know how to use the rules u will be set

Cheers.