SLOPE OR GRADIENT 2

A line passes through (4a, 9) and (8, 5a). If its slope is 2, find a.

Solution

x1=4a, y1 = 9, x2 = 8, y2 = 5a

Slope(m) =    y2 – y1

                     x2 – x1

               2 =  5a – 9

                     8 – 4a

    2 =    5a – 9     [cross multiplying]

    1      8 – 4a

2(8 – 4a) = 5a – 9

16 – 8a = 5a – 9

16 – 8a + 9 = 5a

16 + 9 = 5a+ 8a

25 = 13a

25 = 13a

13    13

²⁵/13 = a

Hence a = ²⁵/13

TRY THIS.................................

A line passes through (4e, 9) and (8, 42e). If its slope is 2, find e.