Question

4 by 6 inch photo is enlarged to a width of 15 inches. What's the new length?

Answer 1

First, you can write a proportion width/legth=width/length
4/6=15/x
Cross multiply (Multiply one denominator times the other numerator and vice versa)
4(x)=6(15)
4x=90
divide both sides by 4
x=22.5.
The new length is 22.5