Answer:
Step-by-step explanation:
-10 ( y-4) + 3y = 5 <--- substitute the value of x into first equation
-10y + 40 + 3y = 5
-7y + 40 = 5
-7y = -35
y= 5
x = 5 - 4
x = 1
X > -4 is the answer to the inequality
I assume you are being asked to solve these equations. Since there wasn't an explanation as to how you are expected to solve them, I chose to demonstrate how to use a calculator matrix function. You can find matrix calculators online. My instructions are for a TI-84
Push the blue 2nd button then push x^-1 button (it says matrix above this button in blue)
Arrow over to edit to change the dimensions of the matrix and to put in your values. You have 3 equations (3 rows) and 4 terms (4 columns) so you put a 3x4 in for the dimension and the coefficients (see images).
You use the rref option in the math column in matrix to calculate the answer.
The numbers at the end are the solutions. x = -4, y = 2, z = -1
Well when u divide 246÷3=82 but since i have to use rectangular models.........
Answer: C) All real values of x such that 
In other words, x must be 0 or smaller.
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Explanation:
The reason why is because we must make the stuff under the square root to never be negative. We must make -2x be 0 or larger.
So,

As an example, if x = -2, then -2x = -2(-2) = 4 is positive. Applying the square root to a positive number is valid.
But if x = 5, then -2x = -2*5 = -10 is under the square root, which is not allowed.