Please help me, it is Hegarty Maths

Cynthia takes her dog to the park every 2 days. she bathes her dog every 7 days. if she took her dog to the park and bathed him today, how long will it be until she does both on the same day again?

The mean of a set of data is -3.82 and its standard deviation is 2.31. find the z score for a value of 3.99.

Simplify. −4x^2 (5x^4−3x^2+x−2) −20x^6−12x^4+8x^3−8x^2 −20x^6+12x^4−4x^3+8x^2 −20x^8+12x^4−4x^2+8x −20x^6+12x^4+4x^3−8x^2