Question

a+b=-1,a-b=9 then find the value of 8ab (a^2+b^2)?​

Answer 1

Answer:

Step-by-step explanation:

Given a+b = -1 →eq.(1)

          a-b = 9

a+b =-1 ⇒ a= -1-b →eq.(2)

substituting eq.(2) in eq.(1)

a-b = 9

-1-b-b = 9

-1-2b =9

2b = 9+1

$b=\frac{10}{2}$  ⇒b = 5

b=5 sub. in eq.(1)

a+b = -1

a+5 = -1

a = -1-5

a = -6

Now we have,

$=8ab(a^{2} +b^{2} )$

$=8(-6)(5)[(5^{2} )+(-6^{2} )]$

= -240 [25+36]

= -240[61]

=-14640

i hope it helped you...... plzz mark this answer as brainliest.