Question

if a+ b is 4 and ab is -12find a^2-b^2​

Answer 1

Step-by-step explanation:

a²+b²=(a+b)²-2ab=4²-2×(-12)=16+24=40 Please mark the answer as brainliest.

Answer 2

$\bold{\huge{\fbox{\color{Black}{Given}}}}$

=> a + b = 4 , ab = -12

$\bold{\huge{\fbox{\color{Black}{Find}}}}$

$= > {a}^{2} - {b}^{2}$

$\bold{\huge{\fbox{\color{Black}{Solution}}}}$

$= > (a + b) = 4$

On Squaring both sides, we get,

$= > {(a + b)}^{2} = {4}^{2} \\ = > {a}^{2} + {b}^{2} + 2ab = 16 \\ = > {a}^{2} + {b}^{2} + 2\times - 12 = 16 \\ = > {a}^{2} + {b}^{2} = 16 + 24 = 40$

Put this value in this equation,

We get,

$= > {(a - b)}^{2} = {a}^{2} + {b}^{2} - 2ab \\ = > {(a - b)}^{2} = 40 - 2 \times - 12 \\ = > {(a - b)}^{2} = 40 + 24 = 64 \\ = > (a - b) = \sqrt{64} = 8$

Now, We know that,

$= > (a + b)(a - b) = {a}^{2} - {b}^{2}$

So,

Put the above values in above equation,

We get,

$= > (4) \times (8) = 32$

So,

$= > {a}^{2} - {b}^{2} = 32$