The rule (x, y) → (4x,4y) maps △abc to △a'b'c' these triangles are not congruent because the image is a dilation of the pre-image. true false

True

Explanation:
For two triangles to be congruent:
1- each side in the first triangle must be congruent to the corresponding side in the second triangle 
2- each angle in the first triangle must be congruent to the corresponding angle in the second triangle.

Now applying the above dilation:
(x,y) > (4x,4y)
We would note that the side lengths of the dilated triangle are larger than those of the original triangle.
Therefore, the first condition for congruency is not satisfied.

This means that dilation would cancel the congruency between the two triangles.

Hope this helps :)