Question

Solve 3x2 + 4x = −5.

Answer 1

move the -5 over by adding 5 to both sides
3x^2+4x+5=0
must use quadratic formula

for an equation in the form
ax^2+bx+c=0
x=
`(-b+/- √(b^2-4ac) )/(2a)`

a=3
b=4
c=5

x=
`(-4+/- √(4^2-4(3)(5)) )/(2(3))`
x=
`(-4+/- √(16-60) )/(6)`
x=
`(-4+/- √(-44) )/(6)`
x=
`(-4+/- 2√(-11) )/(6)`
remember that√-1=i
x=
`(-4+/- 2i√(-11) )/(6)`
x=
`(-2+/- i√(-11) )/(3)`

x=
`(-2+ i√(-11) )/(3)` or x=
`(-2- i√(-11) )/(3)`