Answer:
No, they are not.
Explanation:
6:18 cannot be simplified down to 4:6. 4×1.5=6, but 6×1.5 does not equal 18. 6×3=18, but as ratios work, what we do to one side, we do to the other, 4×3 does not equal 6. Therefore the ratios are not equivalent to each other. Hope this helped. 4:6 has a simplified and equivalent form which is 2:3, and for 6:18, 2:9. The two ratios simplified do not equal to each other as well. This proves my answer even more.