Question

If the slope of the line passing through A(a+3, 5) and B (-5, 2a+1) is 3 find the value of a?

Please help

Answer 1

a = -4

Explanation:

The equation for slope is:

`Slope=(y_2-y_1)/(x_2-x_1)`

We can substitute the given values into the equation:

`3=(2a+1-5)/(-5-(a+3))\\3=(2a-4)/(-5-a-3)\\3=(2a-4)/(-8-a)`

Multiply both sides by -8-a:

`3(-8-a)=2a-4\\\\\text{distribute the 3 to each term in the parentheses}\\\\-24-3a=2a-4\\\\\text{add 4 to both sides}\\\\-20-3a=2a\\\\\text{add 3a to both sides}\\\\5a=-20\\\\\text{divide both sides by 5}\\a=-4`