Answer:
$121.82
Step-by-step explanation:
Okay, this is kind of complex, so let's go step by step.
First, we want to find the area of the rectangular lawn - we can do this by multiplying the length and width. The length is 100 and the width is 45 so
m² is the area of the rectangle.
However, there are 3 ponds in which the grass seeds will not be going - so we need to find the area of all 3 of these circles and subtract it from 4500 (our rectangle area).
The area of a circle is represented by the formula 
The diameters are given here, which is double the radius, so to find the radius of each circle let's divide the diameters by 2.
First circle's radius: 
Second circle's radius: 
Third circle's radius: 
Now let's find the area of each circle.
<em>First Circle</em>: 
<em>Second Circle</em>: 
<em>Third Circle:</em> 
Adding all of these values gets us 412.125.
Now we can subtract from this from 4500 to get us 4087.875
If the grass seeds that cost £1.49 cover 50m² each, then we need
bags.
Each bag costs £1.49, so the total cost is 
Hope this helped!!