Answer:
x=0.5355 or x=-6.5355
First step is to: Isolate the constant term by adding 7 to both sides
Step-by-step explanation:
We want to solve this equation: 
On observation, the trinomial is not factorizable so we use the Completing the square method.
Step 1: Isolate the constant term by adding 7 to both sides

Step 2: Divide the equation all through by the coefficient of
which is 2.

Step 3: Divide the coefficient of x by 2, square it and add it to both sides.
Coefficient of x=6
Divided by 2=3
Square of 3=
Therefore, we have:

Step 4: Write the Left Hand side in the form 

Step 5: Take the square root of both sides and solve for x

Answer:
10 gallons
Step-by-step explanation:
She used 12 gallons this week and used 20% more than last week. That means 12 gallons is 120% of last weeks gas. Since 12 times 10 equals 120, then to find 20% you do 20 divided 10 and subtract the answer from 12.
20% is 2 because 20 divided by 10 is 2. 12 minus 2 is 10
Hope this helps :)
This would be 11.83 I hope you pass your test/quiz :)