Multiply and simplify to lowest terms when appropriate 11/9× 27/55

11/9 * 27/55
First, you need to transform this expression to one fraction, by multiplying the numerators between each other and put the answer as one numerator, then the denominators and put the answer as one denominator.
11/9 * 27/55 = 297/495.
Now comes the simplifying. You need to divide both numerator and denominator by the same number, till you get an irreducible fraction (a fraction In which numerator and denominator can't be divided by the same number to get another whole number).
In this case, both 297 and 495 are divisible by 99.
297/99 = 3 and 495/99 = 5.
So 297/495 = 3/5.
3 and 5 can't be divided by a same number, so 3/5 represents the irreducible and simplified fraction.

You can re-check your answer (very important):
11/9 * 27/55 = 0.6
297/495 = 0.6
3/5 = 0.6
11/9*22/55 = 297/495 = 3/5
The answer has been approved.

Hope this Helps! :) 

A line passing through (3,-4) and (5,1)

find the gradien first
m = y2-y1/x2-x1
m = 1-(-4)/5-3
m = 5/2

and then
the formula is m(x-x1) = y - y1

using (3,-4)
5/2 ( x - 3) = y - (-4)
5/2 (x-3) = y + 4
5(x-3) = 2(y+4)
5x-15 = 2y + 8
5x - 2y -23 = 0

using (5,1)
5/2(x-5) = y - 1
5(x-5) = 2(y-1)
5x-25 = 2y -2
5x -2y-25+2 = 0
5x -2y -23 = 0

so it's the same answer => 5x -2y -23 = 0