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I have to do step by step why the answer of (5x - 1) (5x - 1) is 25x^2 - 10x + 1.

How do i do it?

(5x - 1) (5x - 1)

Ans: 25x^2 - 10x + 1

User Salimah
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1 Answer

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Answer:

(5x - 1)(5x - 1) = 25x² - 10x + 1

Explanation:

Let us solve the question step by step

We need to find the product of (5x - 1) and (5x - 1)

  • The first step multiply 1st term in 1st bracket by 1st term in 2nd bracket (5x by 5x)

∵ 5 × 5 = 25

∵ x × x =
x^(1+1) ⇒ multiply same base means add their powers

∴ x × x = x²

5x × 5x = 25x²

  • The second step multiply 1st term in 1st bracket by 2nd term in 2nd bracket (5x by -1)

∵ 5x × -1 = (5 × -1)x

5x × -1 = -5x

  • The third step multiply 2nd term in 1st bracket by 1st term in 2nd bracket (-1 by 5x)

∵ -1 × 5x = (-1 × 5)x

-1 × 5x = -5x

  • The fourth step multiply 2nd term in 2nd bracket by 2nd term in 2nd bracket (-1 by -1)

∵ -1 × -1 ⇒ (-)(-) = (+)

-1 × -1 = 1

  • The fifth step add them up

(5x - 1)(5x - 1) = 25x² + -5x + -5x + 1

∵ -5x and -5x are like term, then add their coefficients

∵ -5x + -5x = (-5 + -5)x

∴ -5x + -5x = -10x

∴ (5x - 1)(5x - 1) = 25x² + -10x + 1

∵ (+)(-) = (-)

(5x - 1)(5x - 1) = 25x² - 10x + 1

User Jaleh
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