Question

Amir wants to scale up a photo to create a poster for his room. The original picture is 6 inches in width and 4 inches in height. What will be the height of the poster if its width is 30 inches?

Answer 1

The heigh of the poster will be 20 inches

Width= 12 inches

Height= 8 inches

Answer 2

So 6 in.w x 4 inches in.h
what will it be 30 inches wide
$\frac{4}{6}= \frac{x}{30}$
what we are doing right now is putting height over width, then the same thing to the other height over the width
now we cross multiply
(4) (30) = (6)(x)
120 = 6 x
divide both sides by 6 to isolate the variable
20 = x
The height of the poster, that has the width of 30 inches, will be 20 inches

Hope this helps :)