Choose the system of equations which matches the following graph:

a- x + 2y = −10
3x − y = 12

b- x − 2y = −10
3x − y = 12
c- x + 2y = −10
3x + y = 12
d- x − 2y = −10
3x + y = 12

Choose the system of equations which matches the following graph a x 2y 10 3x y 12 b x 2y 10 3x y 12 c x 2y 10 3x y 12 d x 2y 10 3x y 12 class=

Respuesta :

Answer:

Option a

- x + 2y = −10

3x − y = 12

Step-by-step explanation:

step 1

Find the equation of the line with negative slope

we know that

The line with negative slope has a y-intercept at (0,-5)  and passes through the point (2,-6)

Find the slope

[tex]m=(-6+5)/(2-0)=-\frac{1}{2}[/tex]

The equation in slope intercept form is

[tex]y=-\frac{1}{2}x-5[/tex]

Convert to standard form

Multiply by 2 both sides

[tex]2y=-x-10\\x+2y=-10[/tex]

step 2

Find the equation of the line with positive slope

The line with positive slope has a x-intercept at (4,0)  and passes through the point (2,-6)

Find the slope

[tex]m=(-6-0)/(2-4)=3[/tex]

The equation of the line in point slope form is equal to

[tex]y-y1=m(x-x1)[/tex]

we have

[tex]m=3\\point\ (4,0)[/tex]

substitute

[tex]y-0=3(x-4)[/tex]

Convert to standard form

[tex]y=3x-12\\3x-y=12[/tex]

therefore

The system of equations is

- x + 2y = −10

3x − y = 12