Answer:
22
Step-by-step explanation:
22 IS EXACTLY 50% OF 44 SO IN ORDER FOR HER TO GET 50% OF THE QUESTIONS RIGHT IT MEANS SHE ONLY ANSWERED 22 CORRECTLY
The correct first step to solving the system of equations in the most efficient manner is x = -4y +19.
The given system of equations is;

<h2>What is the first step to solving an equation?</h2>
The first step would be to rearrange the variables in the second equation so we have a defined expression for x.
We would want to do this so we could then plug in the defined expression for x into the other equation and solve for the other variable.
x + 4y = 19
Rearrange this by getting the 4y to the other side.
We can get 4y on the other side by subtracting 4y from both sides
x + 4y - 4y = 19 - 4y
x = -4y + 19
Hence, the correct first step to solving the system of equations in the most efficient manner is x = -4y +19.
To know more about the System of equations click the link given below.
brainly.com/question/15240525
Answer:
10x⁴ - 33x² - 7
Explanation:
Before we begin, remember the following:
xᵃ * xᵇ = xᵃ⁺ᵇ
Now, for the given:
To solve the given question, we will multiply each term from the first bracket by each term from the second bracket and then combine like terms to get the final expression.
This can be done as follows:
(5x² + 1)(2x² - 7)
5x²(2x²) + 5x²(-7) + 1(2x²) + 1(-7)
10x⁴ - 35x² + 2x² - 7
10x⁴ - 33x² - 7
Hope this helps :)