Question

3.
If a2 + b2 = 52 and ab = 24 then the value of a2-b2 is
1
20
2
22
3
-22
4
22 and -22​

Answer 1

Answer:

ans (1) 20

Step-by-step explanation:

a²+ b² = 52

a²+ b²+2ab=52+2*24

=52+48=100

(a+b)²=100

a+b=10

also a²+ b²-2ab=52-2*24=52-48=4

so a-b=2

(a+b)(a-b)=10*2=20

a²-b²=20

ans (1) 20

Answer 2

Step-by-step explanation:

(a+b)^2=a^2+b^2+2ab

(a+b)^2=52+48

(a+b)^2=100

a+b=√100

a+b=10

now

(a-b)^2=a^2+^2-2ab

(a-b)^2=52-48

(a-b)^2=4

(a-b)=√4

(a-b)=2

at last

a^2-b^2=(a-b)(a+b)

(a^2-b^2)=(2)(10)

a^2-b^2=20

hence the correct answer is 1.20