How do you write 4 copies of 3 tenths in standard form

Which of the following statements would be sufficient to prove that parallelograms pqrs is a rectangle ?

Petes dog weighed 30 pounds it then lost 16% of it's weight how much did pete lose

Add, subtract, multiply, or divide as indicated. list any restrictions for the variable(s) and simplify the answers when possible. 1) x-2 / x+5 + 3x / 2x-1 2) x+6 / x-6 - x^2 / x+6 3) x+9 / x-4 + x+2 / x^2-11x+28 4) x / x^2-64 + 11 / 2x^2+11x-40 5) 5 / x + 11 / x-3 - x-4 / x^2+2x-15