Question

Use the quadratic formula to solve x2 + 7x + 8 = 0. Estimate irrational solutions to the nearest tenth.

A.
{–12, 5}

B.
{–11.1, –2.9}

C.
{–5.6, –1.4}

D.
{–3.9, 12.1}

Answer 1

x = -7 +/- sqrt(7^2 - 4*1*8)
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2

Answer 2

ok

Answer 3

are you confident in working that out?

Answer 4

i barley started to learn this, so i you can walk through it with me?

Answer 5

ok well use ur calculator
its probably easier to work out sqrt(7^2 - 4*1*8) first

this = sqrt(49 - 32) = sqrt 17

Answer 6

can you find sqrt17 on ur calculator?

Answer 7

yes

Answer 8

4 is the closest

Answer 9

you need to be more accurate than that - find it to the nearest hundredth

Answer 10

my calcuator doesnt do that!

Answer 11

oh ok - are you on a PC?

Answer 12

yes

Answer 13

sorry!

Answer 14

you can use the calculator on that
anyway the answer is 4.12

so you have 2 solutions

-7 + 4.12 -7 - 4.12
-------- and ---------
2 2

Answer 15

yw