The value of y vaires directly with x, and y=18 when x=12. Find y when x=60.
y=90
y=42****
y=1.5
y=40
Am I right?
5 answers
No. Y is greater than x.
That's alright I got it
The value of y vaires directly with x mean:
y and x always have the same ratio k.
k = y / x
In ths case:
k = y / x = 18 / 12 = 6 ∙ 3 / 6 ∙ 2 = 3 / 2 = 1.5
k = y / x
y = k x
When x = 60
y = 1.5 ∙ 60 = 90
y and x always have the same ratio k.
k = y / x
In ths case:
k = y / x = 18 / 12 = 6 ∙ 3 / 6 ∙ 2 = 3 / 2 = 1.5
k = y / x
y = k x
When x = 60
y = 1.5 ∙ 60 = 90
" y varies directly with x" -----> y = kx, k is a constant
given: y=18 when x=12
18 = 12k
k = 3/2
so you have y = (3/2)x
when x = 60 , y = (3/2)(60) = 90
given: y=18 when x=12
18 = 12k
k = 3/2
so you have y = (3/2)x
when x = 60 , y = (3/2)(60) = 90
Tell whether the equation −4x + 2y = 5 represents a direct variation. If so, identify the constant of variation.