Question

If a + b = 9 and a b = 2: 1, find a2-b2..​

Answer 1

Answer:

6

Step-by-step explanation:

a+b = 9

ab = 2:1

using the above we can make a calculation.

the full ratio is 3 (2+1) and the ratio for only A is 2 out of 3 and for B is 1 out of 3, we can write this a fraction

a = 2/3 and b = 1/3, then calculate how many both A and B value by multiplying with 9 since 9 is the value when you add a+b as mentioned in the question.

now you can calculate.

a = 2/3 x 9 ( because 9 is the full amount and we have to find the A part )

a= 6

so we do the same with b,

b = 1/3 x 9

b = 3

so a:b = 6:3

To recheck the answer you can simplify the answer which will give us 2:1 like how its mentioned in the question.

so now we know a = 6 and b= 3

so a2 = 12 and b2 = 6 then,

a2 - b2 is

12 - 6 = 6