Question

If a + b = 3 and ab = 2 find

a^2-b^2​

Answer 1

a+b.=3
Squaring both sides
a^2+2ab+b^2=9
a^2+4+b^2=9
a^2+b^2=9-4=5
I hope it will help you

Answer 2

we know that:-

(a + b)² = a² + b² + 2ab

Now,

(a + b) = 3

[ On SQUARING both side]

(a + b )² = 3²

a² + b² + 2ab = 9

=> a² + b² + 2×2 = 9

=> a² + b² = 9 - 4

=> (a² + b²)= 5