Solve the system by the method of substitution. $\left\{ \begin{array} { l }
0.5 x + 3.2 y = 5.3 \
0.3 x - 1.4 y = - 1.8
\end{array} \right.$
A)(3, 3)
B) $\left( - 1 , \frac { 3 } { 2 } \right)$
C) $\left( 1 , \frac { 3 } { 2 } \right)$
D) $\left( - 1 , - \frac { 3 } { 2 } \right)$
E)(-3, -3)

Question

Solve the system by the method of substitution. $\left\{ \begin{array} { l } 
0.5 x + 3.2 y = 5.3 \
0.3 x - 1.4 y = - 1.8
\end{array} \right.$  
A)(3, 3)
B) $\left( - 1 , \frac { 3 } { 2 } \right)$
C) $\left( 1 , \frac { 3 } { 2 } \right)$
D) $\left( - 1 , - \frac { 3 } { 2 } \right)$
E)(-3, -3)

Quizplus · Accepted Answer

First, solve one of the equations for $x$ or $y$. Let's solve the first equation for $x$: $0.5x = 5.3 - 3.2y$, so $x = 10.6 - 6.4y$. Substitute this expression for $x$ in the second equation: $0.3(10.6 - 6.4y) - 1.4y = -1.8$. Simplify and solve for $y$, then substitute $y$ back into one of the original equations to find $x$. Solving gives $y = \frac{3}{2}$ and $x = 1$, so the correct answer is $\left( 1 , \frac { 3 } { 2 } \right)$.

Solve the System by the Method of Substitution {0.5x+3.2y=5.30.3x−1.4y=−1.8\left\{ \begin{array} { l } 0.5 x + 3.2 y = 5.3 \\0.3 x - 1.4 y = - 1.8\end{array} \right.{0.5x+3.2y=5.30.3x−1.4y=−1.8​

Solve the System by the Method of Substitution $\left\{ \begin{array} { l } 0.5 x + 3.2 y = 5.3 \\0.3 x - 1.4 y = - 1.8\end{array} \right.$