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If 2500x=(455)2тИТ(445)2, then the value of x is:
3.6
4.2
4.8
5.4
6
Observe that the difference (455тИТ445) is 10, so the expression simplifies to 10├Ч(455+445)=10├Ч900=9000. Dividing 9000 by 2500 is equivalent to 90/25, which is 3.6.
An algebraic equation 2500x = (455)2 - (445)2 is provided.
a2тИТb2=(aтИТb)(a+b)
Observe that the difference (455тИТ445) is 10, so the expression simplifies to 10├Ч(455+445)=10├Ч900=9000. Dividing 9000 by 2500 is equivalent to 90/25, which is 3.6.
Many students attempt to calculate the squares 4552 and 4452 individually, which is time-consuming and prone to arithmetic errors.
Identify the Algebraic Identity
The right-hand side of the equation is in the form of a2тИТb2, which can be factored using the identity a2тИТb2=(aтИТb)(a+b).
4552тИТ4452=(455тИТ445)(455+445)
Simplify the Terms
Calculate the difference and the sum of the terms inside the parentheses.
(10)(900)=9000
Solve for x
Substitute the simplified value back into the original equation 2500x=9000 and solve for x.
x=25009000тАЛ=2590тАЛ=3.6
A is correct because the calculation of the difference of squares yields 9000, and dividing by 2500 results in 3.6.
Recognizing the difference of squares pattern is highly useful in simplification-based aptitude questions and quadratic equation solving in higher-level competitive exams.