To find the GCF, first you must factor the 2 or more numbers. The GCF is the highest factor the numbers have in common. for example: you have 12 and 8. If you factor out the numbers for 12, you get 1,2,3,4,6,12 For 8, you get: 1,2,4,8 the GCF of this pair is 4 because it is the highest number that goes into both 8 and 12. To find the LCM, you must find the first number that was multiplied and it must be the same. lets take 3 and 5. Multiply 3 by as many numbers you can think of. For now, lets just go up to 10. 3, 6, 9, 12 15, 18, 21, 24, 27, 30 now to the same for 5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 in both 3 and 5, the first set of numbers that match in 30- therefore the LCM of 3 and 5 in 30. I hope this helps!
The growth rate of a child is not constant, so height versus time does not look like a straight line. Nothing is wrong with the prediction made using the false assumption. You can conclude anything you like when you start with a false premise.
You could work this out with the pythagorean theorem, by proving that 6^2, 36, plus 8^2, 64, equals 100. The fastest way, however, is to use pythagorean triples. These are predetermined sets of numbers that work as side lengths for right triangles. The first two are 3, 4, and 5, which form a right triangle, and 6, 8, and 10, shown here.