Use compatible numbers to find two estimates

What is the order of these fractions from least to greatest 2/3 7/10 5/8 65/100

Gabriel determined that his total cost would be represented by 2.5x + 2y – 2. his sister states that the expression should be x + x + 0.5x + y + y – 2. who is correct? explain.

Suppose the equation ||x-a|-b|=2008 has 3 distinct real roots and a not =0. find the value of b.