Find an equation of the line that satisfies the given conditions. through (−2, −6); perpendicular to the line passing through (1, 6) and (5, 4)

The slope of the given line is ∆y/∆x = (4-6)/(5-1) = -2/4 = -1/2. The slope of the desired (perpendicular) line is the negative reciprocal of this, -1/(-1/2) = 2.

The point-slope form of the equation for a line with slope m through point (h, k) is

... y - k = m(x - h)

For slope 2 and the given point, your equation can be

... y + 6 = 2(x + 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.