A. When you add to negative numbers, it is always negative. A positive + a positive is positive. In D, the answer is always 0. 1 + -1 is 0. In C, it varies. The bigger number not including the negative sign is the sign the number has. For example, -6 + 5 = -1. 6 is bigger than 5. You subtract the smaller number from the bigger number and that is the answer. You would then tack on the negative sign because it is -6, and 6 is bigger than 5.
Answer:
The simplest way to teach middle school math scale drawings is to use real pictures to relate to each other to explain the concept. For example, scaling a red ball of 1" to a ball of 2" and so on. This will show how the ball increases by size by adding 1" each time.
5 cm = 2km
Scale= 5 cm : 200000 cm
= 1 : 40000
a. 1 : 40000 = x : 500000
x = 12.5 cm
b.1 : 40000 = 2 : x
x = 80000 cm
x = 0.8 km
w o w 100 points! t h a n k s :D
