A number is squared, then doubled and then 4 is subtracted. The result is the original number. What could the number be? Give your answers to 2DP

What is the number 321,000,000 in scientific notation? also what is the number? ?

1. are the corresponding angles congruent 2. find the ratios of the corresponding sides 3. is triangle jkl congruent to triangle rst? if so what is the scale factor

Pepe and leo deposits money into their savings account at the end of the month the table shows the account balances. if there pattern of savings continue and neither earns interest nor withdraw any of the money , how will the balance compare after a very long time ?