Theres an app called photomath thats useful for these kinds of problems
1. D
2.B
3.A
4. D i think i can’t really see that question
5.C
Answer:
yes you flip the sign because you are diving by a negative
It should be 15% I think I’m right
the idea of showing that multiplying by 1 is true because as long as A and B follow the same ratio pattern (ie. 1n:2n is the same as 2n:4n) the statement will always be true