Answer:
y= 80/9
Step-by-step explanation:
Given
" y varies directly as x" and "as the square of z" so y = x* z²* some number
if y =25/9 when x= 5, z= 1 and y = x*z²* some number
then 25/9 = 5 * 1² * some number
5*(5/9) = 5 * some number
therefore y = x* z²* (5/9)
y= ? when x=1 , z= 4
y = x * z² * (5/9)
y = 1 * 4² * (5/9)
y = 16*5 / 9
y = 80/9
