Question

what is th evalue of x in the proportion x over x+10 = 7over 12

Answer 1

\[\frac{x}{x+10}=\frac{7}{12}\]
invert
\[\frac{x+10}{x}=\frac{12}{7}\]
\[1+\frac{10}{x}=12/7\]

Answer 2

cross multiply...
12x = 7x +70
5x=70
x=14