Question

Lowest form of x+y by x2-y2 is:
1)x+y
2)x-y
3)x2+y2
4)1/x-y

Answer 1

Answer:

x-y > -2 --> we can have an YES answer, if for example and are both positive ( and ) as well as a NO answer, if for example is positive and is negative ( and ). Not sufficient.

(2) x-2y <-6 --> again it' easy to get an YES answer, if for example and are both positive ( and ) as well as a NO answer, if for example is negative and is positive ( and ). Not sufficient.

You can get that the the two statement individually are not sufficient in another way too: we have (1) and (2) . We are asked whether and have the same sign or whether the points (x,y) are in the I or III quadrant ONLY. But all (x,y) points below the line (for 1) and all (x, y) points above the line cannot lie only in I or III quadrant: points above or below some line (not parallel to axis) lie at least in 3 quadrants.

(1)+(2) Now, remember that we can subtract inequalities with the signs in opposite direction --> subtract (2) from (1): --> . As and (from 1) then (because we can add inequalities when their signs are in the same direction, so: --> ) --> we have that and : both and are positive. Sufficient.

plzz follow me ❤️❤️

Answer 2

Answer:

correct option is 4) 1/x-y