Question

if X proportional y and x1 = 5 y1 = 210, and x2= 2,then find y2= ​

Answer 1

Answer:

if x is proportional with y

it means when x increases y also increase

and when x decrease y also decrease

therfore x=ky

and x/y=k

so,x1/y1=x2/y2=k

here, x1=5,y1=210,x2=2

so, x1y2=x2y1

5×y2=2×210

y2=420/5

y2=84

Answer 2

$x1 = 5 \\ y1 = 210 \\ x2 = 2 \\ \\ \frac{x1}{y1} = \frac{x2}{y2} \\ \\ \frac{5}{210} = \frac{2}{y2} \\ \\ y2 = \frac{2 \times 210}{5} \\ \\ y2 = 2 \times 42 \\ y2 = 84$