12. Find a number t such that the line containing the points
(t, -2)and (-3,5) is perpendicular to the line that contains the
points (3,7) and (5, 11).

Respuesta :

Answer:

t= 11

Step-by-step explanation:

[tex]\boxed{gradient = \frac{y1 - y2}{x1 - x2} }[/tex]

Gradient of line that contains points (3, 7) & (5, 11)

[tex] = \frac{11 - 7}{5 - 3} [/tex]

[tex] = \frac{4}{2} [/tex]

= 2

The product of the gradients of two perpendicular lines is -1.

Gradient of the line that contains points (t, -2) & (-3, 5)

= -1 ÷2

[tex] = - \frac{1}{2} [/tex]

[tex] \frac{ - 2 - 5}{t - ( -3 )} = - \frac{1}{2} [/tex]

[tex] \frac{ - 7}{t + 3} = \frac{ - 1}{2} [/tex]

Cross multiply:

-(t +3)= -7(2)

Dividing by -1 on both sides:

t +3= 7(2)

t +3= 14

t= 14 -3

t= 11