Answer:
[tex]\frac{1}{3}[/tex] or [tex]\frac{140}{420}[/tex]
Step-by-step explanation:
put all your numbers over 420 to make them look like fractions:
[tex]\frac{420}{420}
\frac{280}{420}[/tex]
subtract as normal and simplify if necessary:[tex]\frac{420}{420} -\frac{280}{420} =\frac{140}{420} \\ or \frac{1}{3}[/tex]
