Question

2. if z varies jointly as x2 and the square root of y and if z=75 when x=5 and
4
y=9, find z when x=3, and y=16

Answer 1

Step-by-step explanation:

It is given that z varies jointly as x and the square root of  y if z=6 when x=3 and y=16, therefore,

z=kxy⇒6=k×3×16⇒6=k×3×4⇒12k=6⇒k=126=21     

 

Thus, the general equation is z=21xy.

Since x=7 and y=4, therefore,

z=21xy=21×7×4=21×7×2=7

Hence, z=7 cm when x=7 and y=4. 

Hope it will help you ❣️