The quantity z varies jointly with x and y. If x=-1 and y=-9, and z=-36, find z when x=2 and y=-1.

8

Step-by-step explanation:

let's say xy = kz

when x = -1 and y = -9, then z = -36

so,

xy = kz

(-1)×(-9) = k×(-36)

9 = -36k

k = -1/4

when, x=2 and y=-1

(2)×(-1)=(-1/4)×z

-2=-z/4

z = 8

Answered by GAUTHMATH

180

step-by-step explanation:

x > 1.3

step by step:

8.5−0.9x> 9.8−1.9x

step 1: simplify both sides of the inequality.

−0.9x+8.5> −1.9x+9.8

step 2: add 1.9x to both sides.

−0.9x+8.5+1.9x> −1.9x+9.8+1.9x

1x+8.5> 9.8

step 3: subtract 8.5 from both sides.

1x+8.5−8.5> 9.8−8.5

1x> 1.3

step 4: divide both sides by 1.

1x/1 > 1.3/1