Advertisements
Advertisements
Question
If a2 + b2 = 34 and ab = 12; find : 3(a + b)2 + 5(a - b)2
Sum
Solution
a2 + b2 = 34, ab = 12
(a + b)2 = a2 + b2 + 2ab
= 34 + 2 × 12
= 34 + 24
= 58
(a - b)2 = a2 + b2 - 2ab
= 34 - 2 × 12
= 34 - 24
= 10
3(a + b)2 + 5(a - b)2 = 3 × 58 + 5 × 10
= 174 + 50
= 224
shaalaa.com
Expansion of Formula
Is there an error in this question or solution?
APPEARS IN
RELATED QUESTIONS
Expand : ( x + 8 ) ( x + 10 )
Expand : `( 3a + 2/b )( 2a - 3/b )`
Expand : ( 5a - 3b + c )2
Expand : ( 5x - 3y - 2 )2
Expand : `( x - 1/x + 5)^2`
If a + b + c = 12 and a2 + b2 + c2 = 50; find ab + bc + ca.
If x+ y - z = 4 and x2 + y2 + z2 = 30, then find the value of xy - yz - zx.
If x + 2y + 3z = 0 and x3 + 4y3 + 9z3 = 18xyz ; evaluate :
`[( x + 2y )^2]/(xy) + [(2y + 3z)^2]/(yz) + [(3z + x)^2]/(zx)`
If x = `1/[ 5 - x ] "and x ≠ 5 find "x^3 + 1/x^3`
If x = `1/( x - 5 ) "and x ≠ 5. Find" : x^2 - 1/x^2`
