5.3repeated
Hope this helps
We are given
length of rectangle is 4x-3
width of rectangle is 6x+9
we know that
Area of rectangle = length of rectangle*width of rectangle
so, we can plug value
and we get

now, we can distribute it

now, we can simplify it

...............Answer
-15=11-2b
-11. -11
-26=-2b
-2. -2
13=b