The problem is to remove the brackets and simplify the given expressions. I will solve question number 14: $(7y-1)(7y+1)$.

1. Problem Description

The problem is to remove the brackets and simplify the given expressions. I will solve question number 14: $(7y-1)(7y+1)$.

2. Solution Steps

We need to expand the expression $(7y-1)(7y+1)$. This is in the form of $(a-b)(a+b)$, which is a difference of squares. We can use the following formula:

$(a-b)(a+b) = a^2 - b^2$

Here, $a=7y$ and $b=1$.

So, we have:

$(7y-1)(7y+1) = (7y)^2 - (1)^2$

$(7y)^2 = 49y^2$

$(1)^2 = 1$

Therefore,

$(7y-1)(7y+1) = 49y^2 - 1$

3. Final Answer

$49y^2 - 1$