Solve the system of equations by the substitution method.
-$\left\{ \begin{array} { l }
y = 1.1 x + 3.7 \
y = 0.7 x + 0.98
\end{array} \right.$
A) $( - 6.8 , - 3.78 )$
B) $( 6.8 , - 3.78 )$
C) no solution
D) infinite number of solutions

Question

Solve the system of equations by the substitution method.
-$\left\{ \begin{array} { l } 
y = 1.1 x + 3.7 \
y = 0.7 x + 0.98
\end{array} \right.$
A) $( - 6.8 , - 3.78 )$
B) $( 6.8 , - 3.78 )$
C) no solution
D) infinite number of solutions

Quizplus · Accepted Answer

To solve the system of equations by substitution, we set the two expressions for $y$ equal to each other because they both equal $y$. So, $1.1x + 3.7 = 0.7x + 0.98$. Solving for $x$, we subtract $0.7x$ from both sides to get $0.4x = -2.72$, and then divide by $0.4$ to find $x = -6.8$. Substituting $x = -6.8$ into one of the original equations to find $y$, we use $y = 1.1(-6.8) + 3.7$, which gives $y = -7.48 + 3.7 = -3.78$. Therefore, the solution is $(-6.8, -3.78)$.

Solve the System of Equations by the Substitution Method {y=1.1x+3.7y=0.7x+0.98\left\{ \begin{array} { l } y = 1.1 x + 3.7 \\y = 0.7 x + 0.98\end{array} \right.{y=1.1x+3.7y=0.7x+0.98​

Solve the System of Equations by the Substitution Method $\left\{ \begin{array} { l } y = 1.1 x + 3.7 \\y = 0.7 x + 0.98\end{array} \right.$