Question

Solve the system by graphing
x+4y=8
3x+2y=-6

Answer 1

x + 4y = 8
=> x = 8 - 4y ------> ( 1 )

given that 3x + 2y = -6 , put value of x from ( 1 )

3 ( 8 - 4y ) + 2y = -6
24 - 12y + 2y = -6
24 + 6 - 10y = 0
10y = 30
Divide both sides by 10, we get
y = 3
put the value in ( 1 )

x = 8 - 4 ( 3 )
x = 8 - 12
x = -4
Therfore the solution set = {( - 4, 3 ) }

Answer 2

`\left\{\begin{array}{ccc}x+4y=8\\3x+2y=-6\end{array}\right\\\\-----------------------\\x+4y=8\\4y=-x+8\\y=-(1)/(4)x+2\\for\ x=0\to y=-(1)/(4)(0)+2=2\to(0;\ 2)\\for\ x=4\to y=-(1)/(4)(4)+2=-1+2=1\to(4;\ 1)`



`3x+2y=-6\\2y=-3x-6\\y=-(3)/(2)x-3\\for\ x=0\to y=-(3)/(2)(0)-3=-3\to(0;-3)\\for\ x=-2\to y=-(3)/(2)(-2)-3=3-3=0\to(-2;\ 0)`



`Look\ at\ the\ picture.\\\\Answer:x=-4\ and\ y=3;\ (-4;\ 3).`