Find the best solutions to your problems with the help of IDNLearn.com's expert users. Our platform is designed to provide trustworthy and thorough answers to any questions you may have.

Solve the following system of equations:

[tex]\[
\left\{
\begin{array}{l}
2x + 3y = -3 \\
3x + 5y = -9
\end{array}
\right.
\][/tex]


Sagot :

Sure, let's solve the system of linear equations step by step:

Given system of equations:
1. [tex]\( 2x + 3y = -3 \)[/tex]
2. [tex]\( 3x + 5y = -9 \)[/tex]

Step 1: Start by multiplying each equation by a suitable number so that the coefficients of one of the variables are the same.

Let's eliminate [tex]\(y\)[/tex]. We can do this by multiplying the first equation by 5 and the second equation by 3 to make the coefficients of [tex]\(y\)[/tex] equal.

[tex]\[ \begin{align*} 5(2x + 3y) &= 5(-3) \\ 3(3x + 5y) &= 3(-9) \end{align*} \][/tex]

Which simplifies to:

[tex]\[ \begin{align*} 10x + 15y &= -15 \quad \text{(1)} \\ 9x + 15y &= -27 \quad \text{(2)} \end{align*} \][/tex]

Step 2: Subtract the second equation from the first to eliminate [tex]\(y\)[/tex].

[tex]\[ (10x + 15y) - (9x + 15y) = -15 - (-27) \][/tex]

Simplifying this gives:

[tex]\[ 10x + 15y - 9x - 15y = -15 + 27 \][/tex]

[tex]\[ x = 12 \][/tex]

So, [tex]\( x = 12 \)[/tex].

Step 3: Substitute [tex]\( x = 12 \)[/tex] back into one of the original equations to solve for [tex]\( y \)[/tex]. Let's use the first equation [tex]\( 2x + 3y = -3 \)[/tex]:

[tex]\[ 2(12) + 3y = -3 \][/tex]

[tex]\[ 24 + 3y = -3 \][/tex]

Subtract 24 from both sides:

[tex]\[ 3y = -3 - 24 \][/tex]

[tex]\[ 3y = -27 \][/tex]

Divide by 3:

[tex]\[ y = -9 \][/tex]

So, [tex]\( y = -9 \)[/tex].

Solution: The solution to the system of equations is [tex]\( x = 12 \)[/tex] and [tex]\( y = -9 \)[/tex].

Thus, the solution is:
[tex]\[ (x, y) = (12, -9) \][/tex]