Answer:
y = 10
Step-by-step explanation:
Given y varies jointly as x and z then the equation relating them is
y = kxz ← k is the constant of variation
To find k use the condition y = 20 when x = 4 and z = 3 , then
20 = k × 4 × 3 = 12k ( divide both sides by 12 )
= k , that is
k = 
y = xz ← equation of variation
When x = 2 and z = 3 , then
y = × 2 × 3 = 5 × 2 = 10
The smallest value in this equation would be 0.22
system of equations (1,1)
put value of these x and y in equations
(x , y) = ( 1,1)
so this solution not satisfied equation 1
11( 1) + 3 (1) = 18
so 11 + 3 = 18
15 = 18 ( Left side not equal to right side )
(1,1) is not solution for 11x+ 3y=18
2. 4x+y = 5
put values (1,1)
4(1) + (1) = 5
5 = 5 { left side = right side )
so (1,1) is solution for 4x +y=5
It is D)19 bc 5x3=15 then 7-3=4 so 4x1=4 now 15+4=19
