How to Calculate the slope of the graph.

The equation of slope is rise/ run, or the change in x over the change in y. The actual formula is (x2 - x1)/ (y2-y1). On your graph, you should look at the line, and find 2 points that you know the coordinates of. With the 2 coordinates, the first number is always x and the 2nd number is always y (x,y). Choose one of your coordinate pairs, and take the x value and subtract it from the other x value of the other coordinate pair. Then, in the same order, take the y value from your first coordinate pair and subtract it from the y value in the other coordinate pair. Lastly, divide the x difference by the y difference and that's your slope!  

Example:

Two coordinate pairs: (-2,-1) and (4,3)

-2 and 4 are your x values, and -1 and 3 are your y values.

4-(-2) = 6, and 3-(-1) = 4

therefore, your slope is 6/4, or you can reduce that fraction to 3/2

your finalized slope is 3/2

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.