math
posted by Lea on .
a photo 5 inches wide and 7 inches long is enlarged. The sides of the new photo are in proportion to the original. The new photo is 14 inches wide. how do i find the length

us proportions, then cross multiply:
5/7 = 14/x
5*x = 7*14
5x = 98
5x/5 = 98/5
x = 19.6 inches in length 
This is a good problem for a proportion. Let x equal the new length.
5/14 = 7/x
Cross multiply:
5x = 98
x = 19.6 
7.6x3.5x= 123

7.6x3.5x= 123