If each dimension of a rectangle decreases by 1, its area will decrease from 2017 to 1917. What will be the area of the rectangle if each of its dimensions increases by 1?
let the dimensions be x and y DRAW PICTURES OF THE RECTANGLES
x * y = ?
decrease each of the sides by 1. Now we know that
(x-1)(y-1) = ?
expand this and work out the value of x+y
If you increase the sides by 1 then you have an area of (x+1)(y+1)
expand this then substitute the known values.
Now you have your answer.
Give it a go and get back with what you have done.