Question

If x varies directly with y and x=5, y=210. Find the value of y when x=2?

Answer 1

Answer:

x=5,y=210

Step-by-step explanation:

x=2,y=210/5x2

=42x2

=88

Answer 2

Step-by-step explanation:

$\sf \: x \: varies \: directly \: with \: y$

$\sf \: x \propto y$

$\sf \: x = ky \: \: \: \: (where \: k \: is \: constant)$

$\sf \: at \: x = 5 \: \: \: \: y = 210$

$\sf \: 5 = k(210)$

$\sf \: k = \frac{5}{210} \\ \: \: \: \: = \sf \: \frac{1}{42}$

$\sf \: at \: x = 2$

$\sf \: x = ky$

$\sf \: 2 = \frac{1}{42} y \: \: \: \: \: \\ \sf \: y = 42 \times 2 \\ \sf \: y = 84 \: \: \: \: \: \: \: \:$