20/25 = 4/5 . which method did you use to determine whether this proportion is true or false?
Choose the correct answer:
A) true
B) neutral
C) false
D) not sure
E) none
20/25= 4/5 cross multiplication:   20 * 5= 
<gadget id="calculator">  20 * 5</gadget>
<output>100</output>
100, 4 * 25=100,   we see that 100 are not equal to 100. so there is proportion. corrcet answer: (true)
<result>A</result>
20/25 = 4/5 . which method did you use to determine whether this proportion is true or false?