( x, y ) → ( x-3, y+4 )
A ( 1, 1) → A' (1-3, 1+4) A' (-2, 5)
Answer would be C.
Why A would be incorrect: 100m^2 is 100m × 100 m. That would be as big as a football field.
Why B would be incorrect: 1cm^2 is 1cm × 1cm. You can use a regular 15 cm to measure a piece of paper with the length of 1cm each side.
Why C would be correct: 1m^2 = 1m × 1m and it is also equals to 60cm × 60 cm. A 1 meter ruler = 60 cm = 4 times of your average 15 cm ruler. So, it is reasonable that a classroom is 10m by 10m in length and breadth.
Why D would be incorrect: The same explanation applies to here as well. Things that can be measured with 1m × 1m is a square table so your classroom can't be that small to fit an average of 30 to 40 students in there.
I hope my explanations were detailed and easy to understand. :)
Let b be the number of blue beads and g the number of green beads that Giovanni can use for a belt.
He's supposed to use a total of between 70 and 74 beads, so
70 ≤ b + g ≤ 74
The ratio of green beads to blue beads is g/b, and this ratio has to be between 1.4 and 1.6, so
1.4 ≤ g/b ≤ 1.6
For completeness, Giovanni must use at least one of either bead color, so it sort of goes without saying that this system must also include the conditions
b ≥ 0
g ≥ 0
(These conditions "go without saying" because they are implied by the others. g/b is a positive number, so either both b and g are positive, or they're both negative. But they must both be positive, because otherwise b + g would be negative. I would argue for including them, though.)
