Question

Which line matches the equation?

Answer 1

Answer: 23. D 24. A 25. C 26. B

Explanation:

y=mx+b

The intersection of the straight line with the y-axis equals b

23.

4x+4y=-8

Divide both parts of the equation by 4:

x+y=-2

x+y-x=-2-x

y=-x-2

⇒b=-2 (D)

24.

3x-2y=-6

3x-2y+2y=-6+2y

3x=2y-6

3x+6=2y-6+6

3x+6=2y

Divide both parts of the equation by 2:

1,5x+3=y

⇒ b=3 (A)

25.

x+2y=2

x+2y-x=2-x

2y=-x+2

Divide both parts of the equation by 2:

y=-0.5x+1

⇒ b=1 (C)

26.

3x-y=3

3x-y+y=3+y

3x=y+3

3x-3=y+3-3

3x-3=y

⇒ b=-3 (B)

Answer 2

23) D

24) A

25) C

26) B

Explanation:

23)

4x + 4y = -8 Let's find the intercepts. The x intercept is when y = 0 and the y intercept is when x = 0

Let y = 0

4x + 4y = -8

4x = -8

x = -2

(-2,0)

4x + 4y = -8

Let x = 0

4y = -8

y = -2

(0,-2)

We are looking for the line that goes through the points (-2,0) and (0,-2) That is line D.

24)

3x -2y = -6

Let y = 0

3x = -6

x = -2

(-2,0)

Let x = 0

-2y =-6

y = 3

(0,3)

We are looking for the line that goes through the points (-2,0) and (0,3). That is line A.

25)

x + 2y = 2

Let y = 0

x = 2

(2,0)

Let x = 0

2y = 2

y = 1

(0,1)

We are looking for the line that goes through the points (2,0) and (0,1). That is line C

26)

3x - y = 3

Let y = 0

3x = 3

x= 1

(1,0)

Let x = 0

-y = 3

y= -3

(0, -3)

we are looking for the line that goes through the points (1,0) and (0, -3) which is line B