If you divide the price (10.80) by the weight (7lbs) you would get 1.54 per lbs
Here we are given the equation 3x+k =c
Here in order to solve for x , first let us bring k to the right side.
k is in addition on the left , so when we bring it to the right it gets subtracted

now we have to isolate x on the left side , 3 is in multiplication with x , so when we bring it to the right side we divide by 3
Answer: 
To find the area you multiply the length by the width.
W = the width, and you are told the length is 5 meters longer, so the length would be (W +5)
Now multiply those together to equal 20,000 square meters:
w(w+5) = 20,000