What is the answer to the following calculation with the correct significant digits?

11.49 + 3.359 =

What is the answer to the following calculation with the correct number of significant digits?

(8.8 8.74) 17.9=

What is the answer to the following calculation with the correct significant digits?

11 6.7 =

What is the answer to the following 7.29x10¹² + 6.18x10¹² ?

What is the answer to the following 7.22x10^-3 3.11x10^-3 ?

If x = 2.07 and y = 0.776, what is the value of z?

If x = 18.9 and y = 36.8, what is the value of z?