8(x−3)(3+x)=2x2
To solve the equation 8(x−3)(3+x)=2x2, follow these steps:
- Step 1: Simplify the left side using the difference of squares, which states (a−b)(a+b)=a2−b2. Here, we treat a=x and b=3. This gives us:
(x−3)(3+x)=x2−(3)2=x2−3
- Step 2: Multiply this by 8 as the equation is 8(x2−3).
This results in: 8(x2−3)=8x2−24
- Step 3: Substitute this into the equation to get: 8x2−24=2x2.
- Step 4: Rearrange terms and solve for x by bringing all terms to one side:
8x2−2x2−24=0 which simplifies to 6x2−24=0.
- Step 5: Factor out the common terms in the quadratic equation:
6(x2−4)=0
- Step 6: Notice that using the difference of squares again, x2−4 factors to (x−2)(x+2).
This yields: 6(x−2)(x+2)=0.
- Step 7: Solve (x−2)(x+2)=0 and apply the zero product property:
This gives the solutions x−2=0 and x+2=0, thus x=2 and x=−2.
Therefore, the solution to the problem is ±2.