0
x2-4x -21 = 0
(x-7)(x+3) = 0
x = -3 or x = 7
Alternate
x2 - 4x - 21 = 0
x = (-b ± (b2 - 4ac )(1/2)) ÷ 2a
x = (+4 ± (42 - 4*1*(-21))(1/2)) ÷ 2*1
x = (+4 ± (100)(1/2)) ÷ 2
x = (+4 ± 10) ÷ 2
x = (+2 ± 5)
x = -3 ^ x = +7
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What is a if the square root of 4a squared equals 21?
sqrt(4a2) = 21plus or minus (2a) = 21plus or minus (a) = 10.5a = +10.5a = -10.5
How do you solve 3x minus 6 equals 21?
3x-6 = 21 3x = 21+6 x = (21+6)/3 x = 9 You shouldn't ask us to solve your math homework.
How do you solve 4n minus 7n equals 21?
4n - 7n = 21(4-7) n =21-3n = 21divide both sides by -3n = -7
How do you factor x squared minus 4x minus 21?
x2 - 4x - 21 = (x-7)(x+3)
What is the answer to 16 over 21 minus 2?
16/21 minus two equals -1 5/21
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