Question

if you add two decimals you get one .on multiplying them you get 0.21. What could these decimal be​

Answer 1

Step-by-step explanation:

let x and y be the two decimals

given,

x+y=1. thus x=1-y.

x ×y =0.21

put x= 1-y. in x×y =0.21. we get

(1-y)y = 0.21

y-y²= o.21

y²-y+0.21= 0

y²-0.3y-0.7y+0.21 =0

y(y-0.3) -0.7(y-0.3)=0

(y-0.7)(y-0.3)=0

y=0.3 or y=0.7

if y=0.3. x=0.7

if y=0.7 x=0.3

thus the two decimals are 0.3&0.7