Problem #4: Simone has placed 18 dimes in a row on a table. Always starting from the left, first she exchanges each third coin for a quarter; then she exchanges each second
coin for a nickel; and finally, she exchanges each ninth coin for a penny. In cents, how
much money does Simone have after the final exchange?

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.

What is negative 3/9 times negative 2/8 ?

Given the system of equations presented here: 2x + 4y = 14 4x + y = 20 which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated? multiply the second equation by â’4 to get â’16x â’ 4y = â’80 multiply the second equation by â’1 to get â’4x â’ y = â’20 multiply the first equation by 2 to get 4x + 8y = 28 multiply the first equation by â’1 to get â’2x â’ 4y = â’14