solve for r...10 easy points!!!!?

Question

r^2+3r=2 The solutions are r=????

Answer 1

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r^2+3r-2 = 0

Factorize the equation. then

(r+1)(r-3) = 0

Therefore, r = -1 & 3

Answer 2

r^2+3r=2 => r^2+3r-2=0 => (r+1) (r-3)=0 =>r=3 & -1

Answer 3

r^2 + 3r - 2 = 0

for any quadratic equation of the form

ax^2 +bx + c =0

x = -b +- sqrt (b^2 - 4 * a * c)

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2 * a

Solving this, by the above formula, we get

r = -3 +- sqrt (9-4*1*-2)

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2

= [-3 +- sqrt (17)]/2

=[ -3 +- 4.12]/2

= -7.12/2 or 1.12/2

=- 3.56 and 0.56