Step-by-step explanation:

Answer:
897 liters
Step-by-step explanation:
The motor oil is composed of 8 liters of natural oil and 5 liters of synthetic oil. This means there is a ratio of 8/5. We have 552 liters of natural oil to y liters of synthetic. This is the ratio 552/y. Create a proportion that compares the two ratios.

Solve by cross multiplying.
8y = 5(552)
8y = 2,760
y= 345
345 liters of synthetic oil.
Together 552+345= 897 liters of motor oil.
Answer: First option
Step-by-step explanation:
You have the quadratic equation given in the problem:

To find an equivalent expression you cacn factorize. Find two numbers whose sum is -13 and whose product is -30.
These numbers would be -15 and 2.
Therfore, you obtain the following equivalent expression:

If you don't want to apply the method above, you can use the quadratic formula:

Where:

When you susbstitute values you obtain that:

Then you can rewrite the equation as 
2/3 = 8/12. So the answer is 4/12
To complete the square we get the coefficient of x, divide it by 2 then square it.
-3/4 divided by 2 =
-3/8 and then squared it equals
9 / 64
answer is a