Advertisements
Advertisements
Question
Simplify the following using the formula: (a − b)(a + b) = a2 − b2: (79)2 − (69)2
Advertisements
Solution
Here, we will use the identity \[(a - b)(a + b) = a^2 - b^2\]
Let us consider the following expression:
\[\left( 79 \right)^2 - \left( 69 \right)^2 \]
\[ = \left( 79 + 69 \right)\left( 79 - 69 \right)\]
\[ = 148 \times 10\]
\[ = 1480\]
RELATED QUESTIONS
Simplify the following using the formula: (a − b)(a + b) = a2 − b2: 113 × 87
Simplify the following using the formula: (a − b)(a + b) = a2 − b2: 1.8 × 2.2
Simplify the following using the formula: (a − b)(a + b) = a2 − b2: 9.8 × 10.2
Find the value of x, if 4x = (52)2 − (48)2.
If 2x + 3y = 14 and 2x − 3y = 2, find the value of xy.
[Hint: Use (2x + 3y)2 − (2x − 3y)2 = 24xy]
Evaluate the following: 103 × 96
By using identity evaluate the following:
`1 + 1/8 - 27/8`
Simplify:
(b2 – 49)(b + 7) + 343
Expand the following, using suitable identities.
(x2y – xy2)2
Using suitable identities, evaluate the following.
(98)2
