GRADIENT 1

A line passes through (2a, 7) and (3,5a). If its slope is 10, find a.

Solution

x1=2a, y1 = 7, x2 = 3, y2 = 5a

Slope(m) =    y2 – y1

                     x2 – x1

               10 =  5a – 7

                        3 – 2a

               10 =    5a – 7     [cross multiplying]

               1         3 – 2a

10(3 – 2a) = 5a – 7

30 – 20a = 5a – 7

30 – 8a + 7 = 5a

30 + 7 = 5a+ 8a

37 = 13a

37 = 13a

13    13

a= ³⁷/13

Hence a= ³⁷/13

TRY THIS………………….. 

A line passes through (2a, 6) and (3,5a). If its slope is 12, find a.