Question

If the line joining (3x, x+1) and (11,12) has a slope of 4 what is the value of x​

Answer 1

x = 3

Explanation:

`(3x,\: x +1)=(x_1, \:y_1)`

`(11,\: 12)=(x_2, \:y_2)`

`slope = (y_2 - y_1)/(x_2 - x_1) \\ \\ 4 = (12 - (x + 1))/(11 - 3x) \\ \\ 4 = (12 - x - 1)/(11 - 3x) \\ \\ 4 = (11 - x)/(11 - 3x) \\ \\ 4(11 - 3x) = 11 - x \\ \\ 44 - 12x = 11 - x \\ \\ 44 - 11 = 12x - x \\ \\ 33 = 11x \\ \\ x = (33)/(11) \\ \\ \huge \red{ \boxed{x = 3}}`