Aplot of land doubles in size by adding x meters to the length and x meters to the width of the land. if the original plot had an area of 200 by 300 meters, what is the value of x?

The area of the original plot is 200 x 300 = 60000 

So the problem says 

(x + 200)(x + 300) = 120000 

Proof: 300 x 400 = 120000 

x^2 + 500x + 60000 = 120000 

x^2 + 500x - 60000 = 0 

(x + 600)(x - 100) = 0, so 

x = - 600 (reject), x = 100 

So x = 100 meters 

Proof: 300 x 400 = 120000

The point (5, 10) will work for the rule y=x+5.y= 10 x= 510=5+510=10therefore the ordered pair (5, 10) works for the rule