Show that (3x+7)2-84x = (3x-7)2
Answers
Answered by
8
Answer:
9x^2 - 42^x + 49
Step-by-step explanation
(3x+7)^2 - 84x
= 9x^2 + 42x + 49 - 84x
= 9x^2 - 42x + 49
(3x-7)^2
= 9x^2 - 42x + 49
(a+b)^2 - 4ab = a-b)^2
Answered by
15
☆ (3x + 7)² - 84x = (3x - 7)²
➥ (3x)² + 2 × 3x × 7 + (7)² - 84x
➥ 9x² + 42x + 49 - 84x
➥ 9x² - 42x + 49 = (3x - 7)²
➥ R.H.S.
☆ Hence proved.
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