use the special product formula to factor the perfect square trinomial
4x^2 - 28x + 49
(3x + 7)^2
(2x -2)^2
(3x - 7)^2
(2x - 7)^2
(3x - 49)^2
perfect square trinomial question?
2009-07-20 4:25 pm
回答 (6)
2009-07-20 4:36 pm
✔ 最佳答案
4x^2 - 28x + 49=(2x-7)(2x-7)
=(2x-7)^2 answer//
2009-07-20 11:35 pm
4x² - 28x + 49 = 0
4x² - 28x = - 49
x² - 7x = - 49/4
x² - 7/2x = - 49/4 + (- 7/2)
x² - 7/2x = - 49/4 + 49/4
(x - 7/2)² = 0
x - 7/2 = 0
= x - 7/2, = 2x - 7
Answer: (2x - 7)²
4x² - 28x = - 49
x² - 7x = - 49/4
x² - 7/2x = - 49/4 + (- 7/2)
x² - 7/2x = - 49/4 + 49/4
(x - 7/2)² = 0
x - 7/2 = 0
= x - 7/2, = 2x - 7
Answer: (2x - 7)²
2009-07-21 1:05 am
4x^2 - 28x + 49
= 4x^2 - 14x - 14x + 49
= (4x^2 - 14x) - (14x - 49)
= 2x(2x - 7) - 7(2x - 7)
= (2x - 7)(2x - 7)
= (2x - 7)^2
= 4x^2 - 14x - 14x + 49
= (4x^2 - 14x) - (14x - 49)
= 2x(2x - 7) - 7(2x - 7)
= (2x - 7)(2x - 7)
= (2x - 7)^2
2009-07-20 11:35 pm
4x^2 - 28x + 49
=(2x)^2 - 2*2x*7+(7)^2
=(2x-7)^2
=(2x)^2 - 2*2x*7+(7)^2
=(2x-7)^2
2009-07-20 11:33 pm
Formula (A – B)² = A² – 2AB + B²
Note that 4x² = (2x)² and that 49 = 7², so the only candidate in the list is
(2x – 7)²
It remains to check the middle term 2AB = 2(2x)7 = 28x. Yup, it checks.
Note that 4x² = (2x)² and that 49 = 7², so the only candidate in the list is
(2x – 7)²
It remains to check the middle term 2AB = 2(2x)7 = 28x. Yup, it checks.
2009-07-20 11:31 pm
(2x - 7)^2
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