GRADIENT OR SLOPE 5

The slope of a line which passes through (-5, -12) and (c,-9) is ³/11. Find c.

Solution

x₁ = -5,  y₁ =-12,  x₂ = c,  y₂ = -9

m = y2 –y1

      x2 – x1

  3   =   -9 –(-12)

11         c –(-5)

  3   =    -9 + 12

11          c  + 5

  3   =          3   .

11           c  + 5

3(c + 5) = 3 x 11     [after cross multiplying]

3c + 15 = 33

3c = 33 - 15

3c = 18

3c = 18   

3      3

c = 6   [after dividing by 3 both sides]

Hence the slope is ³/11

TRY THIS………………..

The slope of a line which passes through (-4, -14) and (e,-7) is ³/10. Find e.