Advertisements
Advertisements
प्रश्न
If a - b = 10 and ab = 11; find a + b.
Advertisements
उत्तर
a - b = 10, ab = 11
We know that :
(a - b)2 = a2 - 2ab + b2
⇒ (10)2 = a2 + b2 - 2 x 11
⇒ 100 = a2 + b2 - 22
⇒ a2 + b2
= 100 + 22
= 122
Using (a + b)2 = a2 + b2 + 2ab, we get
(a + b)2
= 122 +2(11)
= 122 + 22
= 144
⇒ (a + b)
= `sqrt(144)`
= ±12.
APPEARS IN
संबंधित प्रश्न
Simplify `(x^2 + y^2 - z)^2 - (x^2 - y^2 + z^2)^2`
Simplify of the following:
(x+3)3 + (x−3)3
Find the following product:
If x = 3 and y = − 1, find the values of the following using in identify:
\[\left( \frac{x}{y} - \frac{y}{3} \right) \frac{x^2}{16} + \frac{xy}{12} + \frac{y^2}{9}\]
Use the direct method to evaluate :
(xy+4) (xy−4)
Evaluate: (2a + 0.5) (7a − 0.3)
Simplify:
(7a +5b)2 - (7a - 5b)2
Factorise the following:
4x2 + 20x + 25
Expand the following:
(4a – b + 2c)2
Expand the following:
(3a – 5b – c)2
