Question

jit4wonsolve each equation by completing the square. round to the nearest hundredth if necessary.
3. x^2+6x =16
4. x^2-10x =11
5. x^2-9x =0
6. x^2+16x =15
7. 3x^2+18x-81=0
use the quadratic formula to solve each equation. round to the nearest hundredth if necessary.
8. 4x^2+3x-8=0
9.2x^2-7x+3=0
10. x^2-2x+3=0
11. 2x^2+4x-7=0

I DONT GET THIS STUFF.

Answer 1

so for quadratic stuff.. Use this formula..\[-b \pm \sqrt{b ^{2}-4ac}/2a\]
like for question 8: a=4; b=3; c=-8 <-- plug these number in the equation and solve..

Answer 2

i knew i was missing a formula lol. thanks.

Answer 3

lol kk welcome.. for completing the sq.. http://www.purplemath.com/modules/sqrquad.htm

Answer 4

for ur question 3. \[x ^{2}+6x=16\]
\[x ^{2}+6x+9\] is a complete sq. so u take 3 inside the brackets and take +9 to the other side.. like,
\[(x+3)^{2}=16+9\]

Answer 5

\[(x+3)^{2}=25\] <-- take the sq. root on both sides..
\[\sqrt{(x+3)^{2}}=\sqrt{5^{2}}\]

Answer 6

\[x+3=\pm5\]

Answer 7

are these the answers?

Answer 8

x=5-3 ; x=-5-3
x=2 ; x=-8
No this is answer to question 3

Answer 9

oh okay thanks.

Answer 10

y welcome

Answer 11

can you do the rest lol?

Answer 12

try doing it, if you get stuck i will help u..

Answer 13

i tried and im stuck. and i have to turn these problems in in 20 mins and its a test.

Answer 14

X^2-6X=20 its saying round to the nearest hundredth can someone help me please