Question

can someone help me with this problem> (picture)

Answer 1

What were you supposed to do?? Solve for x?

Answer 2

44 is wrong

4^2 - 4*4*-7 = 16 + 112 = 128

Answer 3

That doesn't make any sense either.. Where did the square root come from?

Answer 4

im supposed to get 2 asnwers by using the quadratic formula

Answer 5

you left out the -b +/- in the beginning and the 2a in the denominator.

Answer 6

This is the quadratic formula:
\[\frac{ -b \pm \sqrt{b ^{2}-4ac} }{ 2a }\]
For your problem, a = 4, b = 4, and c = -7

So:
\[\frac{ -4\pm \sqrt{4^{2}-4(4)(-7)} }{ 2(4) }\]
x = -1.914 or x = 0.914

Answer 7

But I can't write it in decimal..it has to be square roots

Answer 8

And thats the part I dont know how to do

Answer 9

\[\frac{ -4\pm \sqrt{4^{2}-4(4)(-7)} }{ 2(4) } = \frac{ -4\pm \sqrt{128}}{8}\]

Answer 10

\[\frac{ -4\pm \sqrt{128}}{8} = \frac{ -4\pm \sqrt{64*2}}{8} = -1/2 \pm \sqrt{2}\]

Answer 11

\[x = -1/2 + \sqrt{2} \quad or \ \quad x = 1/2 - \sqrt{2}\]