9.1.3 Points & 9.1.4 Parallel (Straight Lines)

 $y=mx+c$  

 $m$  is gradient
 $c$  is y-intercept

• True

• False

What is the value of gradient, m for $y=-\frac{1}{2}x-2$ ?

(Tips:  $y=mx+c$  )

•  $-2$  

•  $2$  

•  $\frac{1}{2}$  

•  $-\frac{1}{2}$  

What is the value of gradient, m for $y=-6x+9$ ?

(Tips:  $y=mx+c$  )

•  $-6$  

•  $6$  

•  $9$  

•  $-9$  

Which of the following is the equation in the form of $y=mx+c$ for  $3x+6y=-12$ ?

•  $y=3x-12$  

•  $y=-3x+12$  

•  $y=-\frac{1}{2}x-2$  

•  $y=-\frac{1}{2}x+2$  

Straight lines that have the same gradients are parallel.

• True

• False

Determine whether the straight line $3y=-6x+3$  is parallel to the straight line  $y+2x=14$ .

(Tips: Find out the values of gradient for the both equations)
Same value = parallel
Not same value = not parallel

• Parallel
  Gradients of both straight lines equal to 2

• Parallel
  Gradients of both straight lines equal to -2

• Parallel
  Gradients of both straight lines equal to -6

• Not parallel
  Gradients of both straight lines not equal

Determine whether the straight line $y=3x+8$ is parallel to the straight line  $6y=3x-9$ .

(Tips: Find out the values of gradient for the both equations)
Same value = parallel
Not same value = not parallel

• Parallel 
  Gradients of both straight lines equal to 3

• Parallel
  Gradients of both straight lines equal to 6

• Parallel
  Gradients of both straight lines equal to 9

• Not parallel
  Gradients of both straight lines not equal

Determine whether the point P (2, 8) lie on the straight line $y=3x+2$ ?

(Tips: Substitute P (2, 8) into  $y=3x+2$  to compare the value of left-hand side and right-hand side)
Same value = lies
Not same value = does not lie

• P (2, 8) lies on the straight line

• P (2, 8) does not lie on the straight line

Determine whether the point P (4, 3) lie on the straight line $2y=-5x-7$ ?

(Tips: Substitute P (4, 3) into  $2y=-5x-7$  to compare the value of left-hand side and right-hand side)
Same value = lies
Not same value = does not lie

• P (4, 3) lies on the straight line

• P (4, 3) does not lie on the straight line