Answer:
This is absolute value equation so collect like terms and find X
15+5=|x|
20=|x|
since it's absolute value it's going to be 20 or -20
Answer:
1) Let's consider the first case with the number 0 the oppose is also 0 and we have that 0-0=0 so then applies
2) Now let's consider any real number a no matter positive or negative we will have that:

Or in the other case:

So then we can conclude that the expression is a general rule and is true
Step-by-step explanation:
For this case we can verify if the following expression is true or false:
The sum of x and it’s opposite is always zero?
If we want to proof this we need to show that for any number is true.
1) Let's consider the first case with the number 0 the oppose is also 0 and we have that 0-0=0 so then applies
2) Now let's consider any real number a no matter positive or negative we will have that:

Or in the other case:

So then we can conclude that the expression is a general rule and is true
The best way to answer this item is to use the Substitution method. Substitute the value of y from the first equation to the y of the second equation such that the second equation becomes,
-4x + 3(x - 4) = -3
Simplifying the equation,
-x = 9
Dividing both sides by -1 gives an answer of,
<em>x = -9</em>
Then, substitute the value of x in the first equation.
y = -9 - 4
<em> y = -13</em>
The answer to this item is letter B.