(x+2)(2x−4)=2x2+x+10
To solve this problem, we'll follow these steps:
- Step 1: Expand the left-hand side of the equation.
- Step 2: Set the equation to standard quadratic form.
- Step 3: Factor the quadratic equation.
- Step 4: Solve for x.
Let's proceed through each step:
Step 1: Expand the left-hand side using the distributive property:
(x+2)(2x−4)=x(2x)+x(−4)+2(2x)+2(−4)
=2x2−4x+4x−8
=2x2−8
Step 2: Set the equation to quadratic form:
Set the expanded result equal to the right-hand side:
2x2−8=2x2+x+10
Step 3: Subtract the right-hand side from the left:
2x2−8−(2x2+x+10)=0
Simplify:
2x2−8−2x2−x−10=0
−x−18=0
Step 4: Solve for x:
−x=18
Divide by -1:
x=−18
Therefore, the solution to the problem is x=−18.
Checking against the given choices, choice 1 matches: −18.