use cross products to determine which of the following pairs of ratios cannot form a proportion.

Question

1/3 x 3/9
2/3 x 4/9
2/3 x 4/6
1/3 x 2/6
please give step-by-step

Answer 1

1/3 * 3/9
1*9 = 3*3 yes ✅
do the others in the same way. Multiply the two outside numbers and the two inside numbers. If the products are the same, the pair is a proportion.