Question

If y varies directly with x and y= 9/4 when x= 3/2, find y when x= 4/9
.

Answer 1

y=2/3

Explanation:

Again, a simple ratio:

3/2/9/4=4/9/y/1

Multiply inner and outer terms of the complex fraction:

12/18=4/9y

Simplify:

2/3=4/9y

Cross multiply:

18y=12

y=2/3

Answer 2

• The value of y is 2/3 when x = 4/9

------------------------

Direct variation equation:

• y = kx, where k is constant of variation

Use the initial values and find the value of k:

• 9/4 = 3/2*k
• k = 9/4 : 3/2
• k = 9/4 * 2/3
• k = 3/2

Substitute the value of k to get the full equation:

• y = (3/2)x

Find the value of y when x = 4/9:

• y = 3/2*4/9
• y = 2/3

The value of y is 2/3.