really want to improve verbal score

Hi, what is the best strategy to increase my verbal score? I did 2 MGMAT CAT and scored: Quant 1: 40 Verbal 1: 26 Quant 2: 37 Verbal 2: 20 I am using Kaplan Q Bank and MGMAT materials. I always scored better in SC than in CR and in RC. I have been studying GMAT for 2 months and I have insisted mostl...

graph

In the xy-plane, what is the slope of line l?
(1) Line l dose not intersect the line with equation y = 1 - x.
(2) Line l intersects the line with equation y = x – 1.

number properties

If y is the smallest positive integer such that 3,150 multiplied by y is the square of an
integer, then y must be
A. 2
B. 5
C. 6
D. 7
E. 14

sequence

If the sequence x1, x2, x3, …, xn, … is such that x1 = 3 and xn+1 = 2xn – 1 for n ≥ 1, then x20 –
x19 =
A. 2^19
B. 2^20
C. 2^21
D. 2^20 - 1
E. 2^21 - 1

PS

If p is the product of the integers from 1 to 30, inclusive, what is the greatest integer k for
which 3^k is a factor of p?
A. 10
B. 12
C. 14
D. 16
E. 18

Sorry but it is not clear for me.
Could you re explain with an equation.
Thank you

Work problem

For which of the following function f is f(x)=f(1-x) for all x?

A. f(x)= 1-x
B. f(x)= 1-x2 (x square)
C. f(x)= x2 - (1-X)2
D. f(x)= x2(1-X)2
E. f(x)= x/1-x

Thank you

Ali