12345
+ 5.6742
12350.6742 kg
Answer:
Step-by-step explanation:
The submarine is underwater for 6 seconds. The submarine hits the water after 1 second and comes back up at the 7th second.
Answer:
The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown".
Step-by-step explanation:
In x + 2 = 7, x is a variable, but we can work out its value if we try:)