Advertisements
Advertisements
प्रश्न
If a2 + b2 = 74 and ab = 35, then find a + b.
Advertisements
उत्तर
Given, a2 + b2 = 74 and ab = 35
Since, (a + b)2 = a2 + b2 + 2ab ...[Using the identity, (a + b)2 = a2 + b2 + 2ab]
∴ (a + b)2 = 74 + 2 × 35
⇒ (a + b)2 = 144
⇒ `a + b = sqrt(144)` ...[Taking square root]
⇒ a + b = 12 ...[Rejecting – ve sign]
APPEARS IN
संबंधित प्रश्न
Find the following squares by suing the identities.
(b − 7)2
Simplify (4m + 5n)2 + (5m + 4n)2
Using a2 − b2 = (a + b) (a − b), find 512 − 492
Using (x + a) (x + b) = x2 + (a + b) x + ab, find 103 × 98
Expand (ax + by)2
Use an expansion formula to find the value.
(1005)2
Factorise the following, using the identity a2 + 2ab + b2 = (a + b)2.
4x4 + 12x3 + 9x2
The area of a square is given by 4x2 + 12xy + 9y2. Find the side of the square.
The area of a square is 9x2 + 24xy + 16y2. Find the side of the square.
The area of a rectangle is x2 + 7x + 12. If its breadth is (x + 3), then find its length.
