What is the absolute value of - 1/4 is

The vector matrix [2/7] is dilated by a favor of 1.5 and then reflected across the x axis. if the resulting matrix is [a/b] then a= and b=

1. 2. ∠b and ∠y are right angles. 3.? 4.? which two statements are missing in steps 3 and 4? ∠x ≅ ∠c △abc ~ △zyx by the sas similarity theorem. ∠b ≅ ∠y △abc ~ △zyx by the sas similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem.

If the probability of an event happening is 65% then the probability this event does not occur?