We just need to multiply in a x format.
7/15 = x/75
Multiply 7 with 75 and 15 with x.
7 . 75 = 15 . x
525/15 = x
x = 35
[tex]\frac{7}{15} = \frac{x}{75}[/tex] Multiply 75 to both sides of the equation
[tex](75)\frac{7}{15} =\frac{x}{75} (75)[/tex]
[tex]\frac{525}{15} =x[/tex]
35 = x
