Question

in the given subtraction, what is the value of x + y?
1 9 0 7
- x 8
----------
1 8 y 9 pls answer
bad ans will be reported

Answer 1

Answer:

Example 1

We're asked to solve this system of equations:

\begin{aligned} 3x+y &= -3\\\\ x&=-y+3 \end{aligned}  

3x+y

x

​  

 

=−3

=−y+3

​  

 

The second equation is solved for xxx, so we can substitute the expression -y+3−y+3minus, y, plus, 3 in for xxx in the first equation:

\begin{aligned} 3\blueD{x}+y &= -3\\\\ 3(\blueD{-y+3})+y&=-3\\\\ -3y+9+y&=-3\\\\ -2y&=-12\\\\ y&=6 \end{aligned}  

3x+y

3(−y+3)+y

−3y+9+y

−2y

y

​  

 

=−3

=−3

=−3

=−12

=6

​  

 

Plugging this value back into one of our original equations, say x = -y +3x=−y+3x, equals, minus, y, plus, 3, we solve for the other variable:

\begin{aligned} x &= -\blueD{y} +3\\\\ x&=-(\blueD{6})+3\\\\ x&=-3 \end{aligned}  

x

x

x

​  

 

=−y+3

=−(6)+3

=−3

​  

 

The solution to the system of equations is x=-3x=−3x, equals, minus, 3, y=6y=6y, equals, 6.

We can check our work by plugging these numbers back into the original equations. Let's try 3x+y = -33x+y=−33, x, plus, y, equals, minus, 3.

\begin{aligned} 3x+y &= -3\\\\ 3(-3)+6&\stackrel ?=-3\\\\ -9+6&\stackrel ?=-3\\\\ -3&=-3 \end{aligned}  

3x+y

3(−3)+6

−9+6

−3​     =−3 = ?  −3 = ?  −3 =−3 ​  

 

Yes, our solution checks out.

Example 2

We're asked to solve this system of equations:

\begin{aligned} 7x+10y &= 36\\\\ -2x+y&=9 \end{aligned}  

7x+10y

−2x+y =36=9

​  

 

In order to use the substitution method, we'll need to solve for either xxx of yyy in one of the equations. Let's solve for yyy in the second equation:

\begin{aligned} -2x+y&=9 \\\\ y&=2x+9 \end{aligned}  

−2x+y y

​  

 =9 \=2x+9

​  

 

Now we can substitute the expression 2x+92x+92, x, plus, 9 in for yyy in the first equation of our system:

\begin{aligned} 7x+10\blueD{y} &= 36\\\\ 7x+10\blueD{(2x+9)}&=36\\\\ 7x+20x+90&=36\\\\ 27x+90&=36\\\\ 3x+10&=4\\\\ 3x&=-6\\\\ x&=-2 \end{aligned}  

7x+10y

7x+10(2x+9)

7x+20x+90

27x+90

3x+10

3x x =36=36 =36 =36 =4 =−6 =−2

​  

 

Plugging this value back into one of our original equations, say y=2x+9y=2x+9y, equals, 2, x, plus, 9, we solve for the other variable:

\begin{aligned} y&=2\blueD{x}+9\\\\ y&=2\blueD{(-2)}+9\\\\ y&=-4+9 \\\\ y&=5 \end{aligned}  

y y y y

​    

=2x+9

=2(−2)+9

=−4+9

=5

​

The solution to the system of equations is x=-2x=−2x, equals, minus, 2, y=5y=5y, equals, 5.

hope it helps u

Answer 2

Answer:

The value of $x+y$ is $9$.

Step-by-step explanation:

Consider the given subtraction as follows:

$IV$      $III$      $II$       $I$

1          9        0        7

-                      x        8

1         8         y        9

Notice that the subtraction is given in the columnar form. And $I,\ II,\ III,\ IV$ is denoting the number of rows.

In row $I$, the number 8 is subtracted from the number 17 to get the resultant as 9 at units place, i.e.,

$IV$      $III$      $II$       $I$

1          8        9        17

-                      x        8

1         8         y        9

Since borrowing number 1 from the left-side digits.

Now in row $II$, the number $x$ is subtracted from the number 9 to get the resultant as $y$ at units place, i.e.,

$9-x=y$

Rewrite as follows:

⇒ $x+y=9$

Therefore, the value of $x+y$ is $9$.

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