Answer:
The solution of system of equation is (-2,0)
Step-by-step explanation:
Given system of equation are
Equation 1 : 2x+y=(-4)
Equation 2 : y+x=(-1)
To plot the equation of line, we need at least two points
For Equation 1 : 2x+y=(-4)
Let x=0
2x+y=(-4)
2(0)+y=(-4)
y=(-4)
Let x=1
2x+y=(-4)
2(1)+y=(-4)
y=(-6)
Therefore,
The required points for equation is (0,-4) and (1,-6)
For Equation 2 : y+x=(-1)
Let x=0
y+x=(-1)
y+(0)=(-1)
y=(-1)
Let x=2
y+x=(-1)
y+(2)=(-1)
y=(-2)
The required points for equation is (0,-1) and (2,-2)
Now, plot the graph using this points
From the graph,
The red line is equation 1 and blue line is equation 2
Since. The point of intersection is solution of system of equations
The solution of system of equation is (-2,0)
(1) let there be x book and let the total cost be y dollars.
y=19.25x+40
y=16x+69.25
(2) 19.25x+40=16x+69.25
3.25x=29.25
x=9
9 silver book, 9 gold book.
(3) y=19.25x+40=19.25*9+40=213.25 dollars
both companies' total cost are 213.25 dollars.