Answer :
y = kx find k
21 = k*3
k = 7
Equation:
y = 7x
Find x when y = 42
42 = 7x
x = 42/7
x = 6
answer: x = 6 when y = 42
21 = k*3
k = 7
Equation:
y = 7x
Find x when y = 42
42 = 7x
x = 42/7
x = 6
answer: x = 6 when y = 42
y α x
y = cx where c = constant of proportionality
cx = y
c = y/x
y = 21, x = 3, y = 42, x = ?
y/x = c
21/3 = 42/x
7 = 42/x
x = 42/7
x = 6
so x = 6
Hope this explains it.
y = cx where c = constant of proportionality
cx = y
c = y/x
y = 21, x = 3, y = 42, x = ?
y/x = c
21/3 = 42/x
7 = 42/x
x = 42/7
x = 6
so x = 6
Hope this explains it.