Take a look at the problem below. What could you do to eliminate the [tex]$y$[/tex] term from the equations?

[tex]\[
\begin{array}{l}
15x + 7y = 4 \\
5x + 7y = 2
\end{array}
\][/tex]

A. Add the equations
B. Subtract the equations
C. Multiply the equations
D. Divide the equations

After you eliminate the [tex]$y$[/tex] term, you have a one-variable equation that you know how to solve.



Answer :

To eliminate the [tex]\( y \)[/tex] term from the given system of equations, we need to arrange the equations in such a way that when we perform an operation on them, the [tex]\( y \)[/tex] terms cancel each other out. Here are the given equations:

[tex]\[ \begin{array}{l} 15x + 7y = 4 \\ 5x + 7y = 2 \end{array} \][/tex]

To eliminate the [tex]\( y \)[/tex] term, we can subtract the second equation from the first. Let's do this step by step.

First, write down the system of equations clearly:

1. [tex]\( 15x + 7y = 4 \)[/tex]
2. [tex]\( 5x + 7y = 2 \)[/tex]

Step 1: Subtract the second equation from the first:

[tex]\[ (15x + 7y) - (5x + 7y) = 4 - 2 \][/tex]

Step 2: Simplify the left-hand and right-hand sides of the resulting equation:

The left-hand side simplifies as follows:
[tex]\[ 15x + 7y - 5x - 7y \][/tex]
Since [tex]\( +7y \)[/tex] and [tex]\( -7y \)[/tex] cancel each other out, we are left with:
[tex]\[ 15x - 5x = 10x \][/tex]

The right-hand side simplifies to:
[tex]\[ 4 - 2 = 2 \][/tex]

So, the simplified equation is:
[tex]\[ 10x = 2 \][/tex]

Step 3: Solve for [tex]\( x \)[/tex]:

[tex]\[ x = \frac{2}{10} \][/tex]
[tex]\[ x = 0.2 \][/tex]

Therefore, after eliminating the [tex]\( y \)[/tex] term and solving the simplified one-variable equation, we find:
[tex]\[ x = 0.2 \][/tex]