Firstly you multiply 5 with everything in the brackets on the left side of = . and than you put t on the left side and change sign (if it was + then its going to be -) and numbers on right side and do the same with signs. then just calculate the rest
5(5t +1) = 25t - 7
25t + 5 = 25t - 7
25t - 25t = -7 + 5
0=-2
the statement is false
Y= 4 - 4/5x all you have to do is make it go up 4 from 0 and either go down 4 and go right 5 or up 4 and to the left 5... hope this helped!
The answer would be the first choice. 
Explanation: The reason for this is that the question was pretty much just asking what the area of the resulting two-dimensional cross section would be -the shape in gray- (which can be found by using the formula
. To add on, since the dimensions of the shape are already given (5 and 3) all you've to do is multiply: 3*5=15
That's how you get to the answer.
5^3(5^x) the rule is a^b(a^c)=a^(b+c)
5^(3+x)