if the mesure of one angle created by the intersection of 2 lines is 90 degrees then all 4 of the angles created by the intersection of 2 lines will measure 90 degrees true or false

How do you use the elimination method for this question? explain, because i really want to understand!

The fraction of defective integrated circuits produced in a photolithography process is being studied. a random sample of 300 circuits is tested, revealing 17 defectives. (a) calculate a 95% two-sided confidence interval on the fraction of defective circuits produced by this particular tool. round the answers to 4 decimal places. less-than-or-equal-to p less-than-or-equal-to (b) calculate a 95% upper confidence bound on the fraction of defective circuits. round the answer to 4 decimal places. p less-than-or-equal-to

If t8 = 4 and t12 = −2, find the first three terms of the arithmetic sequence.