5x+2y=7
7x+2y=5 i need it right

Acircle has a circumference of 28.36 units what is the diameter of the circle

Im literally having a mental breakdown

One astronomical unit (1 au) is about 1.496 alt tag missing. kilometers. if you wrote this number of kilometers in regular decimal notation (for example, 528 and 3,459 are written in regular decimal notation), how many zeros would your number have?