Question

39. Solve this system: 3x+y=-7 . 4x-y=14A. (–1, 10)B. (1, –10)C. (–1, –10)D. no solution

Answer 1

Given,

The linear pair of the equation is,

$\begin{gathered} 3x+y=-7 \\ 4x-y=14 \end{gathered}$

Required

The solution of the linear equation.

Taking the equation first as,

$\begin{gathered} 3x+y=-7 \\ y=-7-3x \end{gathered}$

Substituting the value of y in second equation then,

$\begin{gathered} 4x-y=14 \\ 4x+7+3x=14 \\ 7x+7=14 \\ 7x=7 \\ x=1 \end{gathered}$

Substituting the value of x in first equation then,

$\begin{gathered} 3x+y=-7 \\ 3(1)+y=-7 \\ y=-7-3 \\ y=-10 \end{gathered}$

Hence, the solution of the system is (1, -10).