0.63 Divided by 9 pls give me the correct answer!

The lengths of two sides of a right triangle are given. find the length of the third side. round to the nearest tenth if necessary. a) y = 12/5x + 39/5 b) y = 5/12x + 5/39 c) y = 12/5x - 39/5 d) y = 5/12x - 5/39

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

The square root of 9x plus 7 plus the square rot of 2x equall to 7