The zero product property tells us that if the product of two or more factors is zero, then each one of these factors CAN be zero.
For more context let's look at the first equation in the problem that we can apply this to:

Through zero property we know that the factor

can be equal to zero as well as

. This is because, even if only one of them is zero, the product will immediately be zero.
The zero product property is best applied to
factorable quadratic equations in this case.
Another factorable equation would be

since we can factor out

and end up with

. Now we'll end up with two factors,

and

, which we can apply the zero product property to.
The rest of the options are not factorable thus the zero product property won't apply to them.
Answer:
C
Step-by-step explanation:
3/4 of 1000 is 750 and 1/5 of 750 is 150 so your answer is C
Answer:
56
......................................................
To calculate the square root, you can either use the √symbol on a calculator or you can manually find it using Prime Factorization. For non-perfect squares, Prime Factorization is the way to go.
The first two steps work for solving large perfect squares as well.
1. Divide your number into perfect square factors.
2. Take the square roots of your perfect square factors.
3. If your number doesn't factor perfectly, reduce your answer to simplest terms.
4. If needed, estimate. In some cases if you have memorized some of the square roots, you can estimate where the number would be.
ie.

you know that

and

, so you can estimate that the

would be between 7 and 8 but closer to 8.
5. <span>Alternatively, reduce your number to its lowest common factors as your first step.</span><span> Finding perfect square factors isn't necessary if you can easily determine a number's prime factors (factors that are also prime numbers).
ie. </span>

=

=

=

Hope this helped!!!
19+x/2=4
multiply 2 on both sides
19+x=4 times 2
19+x=8
subtract 19 on each side
x=8-19
subtract
x=-11