Solve. x^2 + 5 = 21 please help........Solve. 9x^2 = 14.....do?

Question

. (x – 4)2 = 3
5(x – 2)2 = 3
Is the following trinomial a perfect square?x2 – 2x + 1
Is the following trinomial a perfect square?x2 + 4x – 4
Find the constant term that should be added to make the following expression a perfect-square trinomial.x2 + 3x
Solve by completing the square. x2 + 4x + 3 = 0
Solve by completing the square. x2 = 5x + 2
Solve by using the quadratic formula. x2 = 3x + 12
can someone please help me with these problems if i don't solve them i have failed my class...........please

Answer 1

So you want to cheat rather than learn? Why not ask your teacher for help? Or a tutor?

Answer 2

Equation: 9x^2 = 14
Solving: Subtract 9 from both sides of the equal sign, thus
x^2 = 5
Since you're solving for x, you need to take the square root, thus
x= the square root of 5.

Equation: x^2 + 5 = 21
Solving: Same as before, we need to find x, not x^2. So, subtracting 5 from both sides, we have
x^2 = 16
Taking the square root, we have
x = 4


That's all I'll help you with. If you can't figure the others out on your own, try looking in your textbook, as that's where the questions come from. It also helps to take a short break if you've been studying for a long time and can't think straight anymore. Hope that helps, and good luck!

Answer 3

x^2 + 5 = 21 --- x^2 = 16 --- x^2=sqrt16 --- x = +4, x = -4

9x^2 =14 --- x^2 = 14/9 --- x = +(sqrt14)/3, x = -(sqrt14)/3

x^2 - 2x + 1 is a perfect square trinomial

x^2 + 4x - 4 is not

+9/4 must be added

x = -3 x = -1

im bored to answer the rest quadratic is
x= (-b +/- sqrt(b^2 - 4ac))/2 where a is the coefficient of x^2 b is the coefficient of x and c is the constant

Answer 4

x^2 + 5 = 21
x^2 = 16
x = -4 or 4

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9x^2 = 14
x^2 = (14/9)
x = (sqrt(14))/3 or (-sqrt(14))/3

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(x - 4)^2 = 3
x - 4 = sqrt(3)
x = 4 ± sqrt(3)

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x^2 - 2x + 1 = (x - 1)^2
ANS : Yes

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x^2 + 4x - 4
If you complete the square you will get
ANS : No

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x^2 + 3x
find half of 3 and square it
x^2 + 3x + (9/4)

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x^2 + 4x + 3 = 0
x^2 + 4x = -3
find half of 4, square it, add to both sides
x^2 + 4x + 4 = -3 + 4
x^2 + 4x + 4 = 1
factor the left side into a perfect square
(x + 2)^2 = 1
sqrt both sides
x + 2 = ±1
subtract both sides by 2
x = -2 ± 1
x = -3 or -1

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x^2 = 5x + 2
x^2 - 5x = 2
x^2 - 5x + (25/4) = 2 + (25/4)
x^2 - 5x + (25/4) = (8/4) + (25/4)
x^2 - 5x + (25/4) = (33/4)
(x - (5/2))^2 = (33/4)
x - (5/2) = (±sqrt(33)/2)
x = (5/2) ± (sqrt(33)/2)
or
x = (1/2)(5 ± sqrt(33))

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x^2 = 3x + 12
x^2 - 3x - 12 = 0

x = (-b ± sqrt(b^2 - 4ac))/2a

x = (-(-3) ± sqrt((-3)^2 - 4(1)(-12)))/(2(1))
x = (3 ± sqrt(9 + 48))/2
x = (3 ± sqrt(57))/2
x = (1/2)(3 ± sqrt(57))

Answer 5

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Answer 6

x^2+5=21
x^2+5-5=21-5=16
√x^2=√16
x=4

errrm i have to go but e-mail me and i'll help with the rest later kk? laterz