Answer:
49
Explanation:
Every time you multiply both sides of a rectangle by a number x, its area if multiplied by
.
In our example:
Area of a rectangle = width . length
width = 4
length = 7
= 4 . 7 = 28
When you multiply both sides by 7:
width = 4 . 7 = 28
length = 7 . 7 = 49
= 28 . 49
= 1372
/
= 1372 / 28 = 49 =

Both sides multiplied by 7 => Area multiplied by

Got it?
;-)