Algebra · real student question

Solve the equation x^2 + 3x = -2.

Question

Solve

x2+3x=2x^2+3x=-2

Step-by-step solution

  1. Get a zero on one side. Factoring and the zero-product property both require standard form, so add 22 to both sides:

    x2+3x+2=0x^2+3x+2=0

  2. Find the factor pair. With a leading coefficient of 11, look for two numbers whose product is the constant 22 and whose sum is the middle coefficient 33. Those are 11 and 22:

    x2+3x+2=(x+1)(x+2)x^2+3x+2=(x+1)(x+2)

  3. Set each factor to zero. A product is zero only if one of its factors is zero:

    x+1=0  x=1,x+2=0  x=2x+1=0\ \Rightarrow\ x=-1,\qquad x+2=0\ \Rightarrow\ x=-2

  4. Predict the signs as a sanity check. Both the sum (3-3) and the product (+2+2) of the roots are consistent with two negative roots, which is what we found — a quick structural check before substituting.

  5. Substitute into the original equation. At x=1x=-1: 13=21-3=-2 \checkmark. At x=2x=-2: 46=24-6=-2 \checkmark.

Answer

x=1orx=2x=-1\quad\text{or}\quad x=-2

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