how do i solve the following: 3r^2+4r=-5

Question

Not sure how to go about answering this problem, please help.

Answer 1

3r^2 + 4r = -5

3r^2 + 4r + 5 = 0

this doesn't factor nicely, so quadratic formula

If ax^2 + bx + c = 0 then x = (-b +- sqrt(b^2-4ac) )/2a

r = (-4 +- sqrt(4^2 - 4(3)(5) )/2(3)

r = (-4 +- sqrt(16 - 60) )/6

r = (-4 +- sqrt(-44) )/6

You can't take the square root of a negative number, so there is no solution.

No value of r will make 3r^2 + 4r = -5 true.