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Question

Question: How do you solve \(\left| y \right|=5\) ?...

How do you solve y=5\left| y \right|=5 ?

Explanation

Solution

To solve the above given expression, we should know the concepts of absolute values and modulus. The modulus function, or the absolute value of a number implies that x=x\left| x \right|=x and is equal to xx if x0x\ge 0 or is equal to x-x if x<0x < 0 .

Complete step-by-step answer:
Given the expression:
y=5\Rightarrow \left| y \right|=5
In the given expression the value of yy can be greater than zero, that is, it can be a positive number, or it can also be lesser than zero indicating that it is a negative number.
Therefore, the expression can be simplified and also written asy=±5y=\pm 5 .
This equation or expression given above, also represents the equation of a line that is parallel to the xx - axis and passes through the point y=5y=5 on the yy - axis. Since, the line is parallel to the horizontal or xx - axis, the slope of the line will be zero.
The slope-intercept form of the above line can be written as y=0x+5y=0x+5 , where 00 represents the slope of the line and 55 represents the constant in the equation of the line. The same concept will be applied to the graph of y=5y=-5 as well.
The graph for the above equation y=5\left| y \right|=5 can be represented as below,

The graph can be plotted by taking and substituting different values of xx in the equation y=0x+5y=0x+5 and then calculating the respective values for yy. For example, if we take x=1x=1 and substitute the value in the given equation, we get,
y=0(1)+5\Rightarrow y=0\left( 1 \right)+5
On simplifying the above equation, we get the value of yy as,
y=5\Rightarrow y=5
Similarly, we can take different values for xx and find the value for yy.
In the same manner, we can also plot the graph for y=0x5y=0x-5 or y=5y=-5 by taking different values of xx and then finding the corresponding values for yy.
Therefore, on solvingy=5\left| y \right|=5, we gety=±5y=\pm 5

Note: Absolute value of a number means how far the number is from zero on the number line. This also means that while finding the absolute value of a given number, we remove any negative sign in front of the number and take its positive value only.