Question

Solve for a: 4a/9=100/45

Answer 1

How about doing this?
Multiply both sides by 9.
Multiply both sides by 45.
Solve a beautiful linear equation.

Answer 2

cancel 5 ie common in 100/45 n proceed

Answer 3

\[ \color{Black}{\Rightarrow {4a \over 9} \times 9 = {100 \over 45} \times 9}\]etc

Answer 4

a=5