1. The slope is -2/5 not 3-/10
Let us assume the number to be = x
Then
(80/100) * x = 56
4x/5 = 56
4x = 56 * 5
4x = 280
x = 280/4
= 70
The value of the unknown number is 70. I hope the procedure is clear enough for you to understand. You can always use this method for solving similar problems in future without requiring any help from outside. Only thing that needs to be taken care of is the calculation part.
ANSWER: 
EXPLANATION:
We can use the slope formula and input the x and y values to solve for the slope.


The slope of the line is 
Answer:
2.83 units diagonally
2 units horizontally and 2 units vertically
Step-by-step explanation:
x position difference -2-(-4)=2
y position difference 7-5=2
2 units horizontally and 2 units vertically on a graph
2^2+2^2=8
sq rt 8=2.83 units