Question

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Answer 1

Question :-

Show that (2a - 5)² + 40a = (2a + 5)²

Formula to use :-

☞ (a - b)² = a² - 2ab + b²

☞ (a + b)² = a² + 2ab + b²

For any equation to hold true, the LHS (Left hand side) must be = to the RHS (Right hand side)

Solving LHS and RHS separately,

LHS :-

(2a - 5)² + 4a

• a = 2a
• b = 5

☞ [(2a)² - 2(2a)(5) + (5)²] - 40a

☞ (4a² - 20a + 25) + 40a

Removing the brackets,

☞ 4a² - 20a + 25 + 40a

☞ 4a² + 25 + 20a

By rearranging,

☞ 4a² + 20a + 25

RHS :-

(2a + 5)²

• a = 2a
• b = 5

☞ (2a)² + 2(2a)(5) + (5²)

☞ 4a² + 20a + 25

LHS = RHS

Hence Verified.

Hope it helps!

Happy day!