PLEASE HELP WILL AWARD BRAINLIEST IF GOOD EXPLANATION THANK YOU x varies directly with y and inversely with . If x = 3 and y = 12 when z = 2, find y when x = 1 and z = 4.

16

Step-by-step explanation:

x∞y/z²

x=ky/z²(where k is the constant)

3=12/2²k

3=12/4k

3=3k

3÷3=k

therefore k=1

x=1y/z²

making y the subject

xz²=y

1(4²)=y

1×16=y

16=y

-13

step-by-step explanation:

f(x)=2x-5 for f(-4)

f(-4)   means let x=-4

f(-4) = 2(-4) -5

f(-4) =-8-5

      = -13