¿cuáles de estas estrategias eliminan una variable en el sistema de ecuaciones? { 2 x + 3 y = − 5 2 x − 3 y = 10 ⎩ ⎪ ⎪ ⎨ ⎪ ⎪ ⎧ 2x+3y=−5 2x−3y=10

What is the measure of angle z in this figure? enter your answer in the box. z = ° two intersection lines. all four angles formed by the intersecting lines are labeled. clockwise, the angles are labeled 43 degrees, x degrees, y degrees, and z degrees.

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years

Amachine that produces a special type of transistor (a component of computers) has a 2% defective rate. the production is considered a random process where each transistor is independent of the others. (a) what is the probability that the 10th transistor produced is the first with a defect? (b) what is the probability that the machine produces no defective transistors in a batch of 100? (c) on average, how many transistors would you expect to be produced before the first with a defect? what is the standard deviation? (d) another machine that also produces transistors has a 5% defective rate where each transistor is produced independent of the others. on average how many transistors would you expect to be produced with this machine before the first with a defect? what is the standard deviation? (e) based on your answers to parts (c) and (d), how does increasing the probability of an event a↵ect the mean and standard deviation of the wait time until success?