Answer: The area of the enlargement is 315cm.
Explanation:
If the picture has 35cm as the area and it has a length of 7cm then we can find the width by dividing the area by the length.
w= 35/7
w = 5
So in this care the width of the picture in 5cm.
Now is saying that the picture's length has been enlarge or been dilated to 21 cm. To get from 7cm to 21cm you will have to multiply by 3.
In this situation, we will have to multiply the original picture's width by 3 to find it enlargement.
w= 5*3 = 15
The width is 15cm and the length is 21cm so multiply them to find the area.
A = 15 * 21
A = 315cm