The variable z varies jointly with x and y. also, z = -75 when x = 3 and y = -5. what equation describes this variation? what is the constant of variation? k =

z = 5xy

Step-by-step explanation:

since z varies jointly with x and y then

z = kxy ← k is the constant of variation

to find k use the given condition z = - 75 when x = 3 and y = - 5

k = = = 5 and

z = 5xy ← equation of variation

4 packs of water and 7 packs of candy bars

step-by-step explanation:

35x4=140

140/20=7

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.