Question

Solve 3x2 + 18x + 15 = 0 by completing the square.

3(x + 3)2 = 6; x = −3 + square root 2, x = −3 − square root 2
3(x + 9)2 = 12; x = −11, x = −7
3(x + 3)2 = 12; x = −5, x = −1
3(x + 9)2 = 228; x = −9 + square root 76, x = −9 − square root 76

Answer 1

divide by 3

Answer 2

\[x^2+6x+5=0\]
\[x^2+6x=-5\]
add both sides \[\left( \frac{ 6 }{ 2 } \right)^2 ~i.e.,9\]
\[x^2+6x+9=-5+9\]
\[\left( x+3 \right)^2=2^2\]
\[x+3=\pm2,x=?\]

Answer 3

4?

Answer 4

no

Answer 5

x+3=2
x=?

Answer 6

-1

Answer 7

correct
and x+3=-2
x=?

Answer 8

-5

Answer 9

correct
these are two values of x

Answer 10

THANK YOUUUU :)

Answer 11

yw