Answer:

Step-by-step explanation:
First, rewrite the given equation in the form of y=mx+c.
m is the gradient while c is the y-intercept.
3x-5y=8
5y= 3x -8

Thus, the gradient of the given equation is ⅗.
The product of the gradients of perpendicular lines is -1.
(gradient of line)(⅗) = -1
gradient of line= -1 ÷⅗
gradient of line= 

To find the value of c, substitute a coordinate.
When x=3, y=7,

7= -5 +c
c= 7+5
c= 12
Hence, the equation of the line is
.
Answer:
x=4
Step-by-step explanation:
Pentagon's sum of interior angle is 540°
let's add all the given degrees
100+20x+16x+16+140+160-5x=540
Collect like terms
100+16+140+160+20x+16x-5x=540
416+31x=540
31x=540-416
31x=124
x=124/31
x=4```
12 because six people came to the party and you shake their hand