if a+b =8 and ab = 15 find a^2 +b^2
Answers
Answered by
47
a + b = 8, ab = 15
(a+b)^2 = (8)^2
a^2 + b^2 + 2ab = 64
a^2 + b^2 + 2(15) = 64
a^2 + b^2 + 30 = 64
a^2 + b^2 = 64 - 30
a^2 + b^2 = 34
(a+b)^2 = (8)^2
a^2 + b^2 + 2ab = 64
a^2 + b^2 + 2(15) = 64
a^2 + b^2 + 30 = 64
a^2 + b^2 = 64 - 30
a^2 + b^2 = 34
Answered by
27
given,
a +b=8
after squaring both sided we get,
(a +b) ^2=8 ^2
a ^2 +b ^2 +2ab= 64
a ^2 +b ^2 +2× 15 = 64 (ab= 15)
a ^2 +b ^2 + 30= 64
a ^2 +b ^2= 64- 30
a ^2 +b ^2= 34.
a +b=8
after squaring both sided we get,
(a +b) ^2=8 ^2
a ^2 +b ^2 +2ab= 64
a ^2 +b ^2 +2× 15 = 64 (ab= 15)
a ^2 +b ^2 + 30= 64
a ^2 +b ^2= 64- 30
a ^2 +b ^2= 34.
Similar questions