Advertisements
Advertisements
Question
Which of the following is correct?
Options
(a – b)2 = a2 + 2ab – b2
(a – b)2 = a2 – 2ab + b2
(a – b)2 = a2 – b2
(a + b)2 = a2 + 2ab – b2
Advertisements
Solution
(a – b)2 = a2 – 2ab + b2
Explanation:
We have,
(a – b)2 = (a – b)(a – b)
= a(a – b) – b(a – b)
= a · a – a · b – b · a + b · b
= a2 – ab – ab + b2 ...[∵ a · b = b · a]
= a2 – 2ab + b2
And (a + b)2 = (a + b)(a + b)
= a · a + a · b + b · a + b · b
= a2 + 2ab + b2
APPEARS IN
RELATED QUESTIONS
125 + 8x3 - 27 y3 + 90xy
If \[x^2 + \frac{1}{x^2} = 18,\] find the values of \[x + \frac{1}{x} \text { and } x - \frac{1}{x} .\]
Multiply: x2 + 4y2 + 2xy − 3x + 6y + 9 by x − 2y + 3
Multiply: 9x2 + 25y2 + 15xy + 12x − 20y + 16 by 3x − 5y + 4
The value of \[\frac{(2 . 3 )^3 - 0 . 027}{(2 . 3 )^2 + 0 . 69 + 0 . 09}\]
Multiply: (x - a)(x + 3b)
Express the following as an algebraic expression:
The product of 12, x, y and z minus the product of 5, m and n.
Write the coefficient of x2 and x in the following polynomials
`6 - 2x^2 + 3x^3 - sqrt(7)x`
The value of 7a – 4b when a = 3, b = 2 is
A student wrote an algebraic expression for “5 less than a number n divided by 3” as `n/3 - 5`. What error did the student make?
