Determine whether the two expressions are equivalent. if so, tell what property is applied. if not, explain why. 0+32 and 0

Could someone with number 1 and 2

Aproduction manager test 10 toothbrushes and finds that their mean lifetime is 450 hours. she then design sales package of this type of toothbrush. it states that the customers can expect the toothbrush to last approximately 460 hours. this is an example of what phase of inferential statistics

Which equation shows the quadratic formula used correctly to solve 5x2 + 3x -4 0 for x? cos -3+ v (3) 2-4() 2(5) 3+ |(3)² +4() 205) 3+ (3) 2-4() -3+ v (3)² +4()