The total income of a factory this year is 7.2 million yuan, and the total income of this year is more than the total income of last year (1/8). Find the total income of the factory last year?
某工厂今年生产总收入为720万元，今年的总收入比去年的总收入多(1/8)，求工厂去年的总收入？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 + (1/8)</gadget>
<output>9/8 = around 1.125</output>

<gadget id="calculator">720 / (9/8)</gadget>
<output>640</output>

<result>640</result>