Question

1. What is the equation, in slope-intercept form, of the line that passes through (0, 5) and has a slope of −1?
y = −x − 5
y = x + 5
y = −x + 5
y = x − 5

2. An electrical company uses the function f(h) = 15h + 75 to calculate the total repair bill, f(h), for h number of hours worked. Find h if f(h) = $225.
10 hours
15 hours
3,375 hours
3,450 hours

3. Solve the following for y: 4x + 2y = −2
y = −2x + 1
y = 2x + 1
y = −2x − 1
y = 2x − 1

Answer 1

1. The slope is the number that is multiplied by X, since the slope is -1, when multiplied by X you would get -X, the y intercept is the given y coordinate (5), so the equation would be y = -x+5

2. Replace f(h) with 225 and solve for h:

225 = 15h +75

Subtract 75 from each side:

150 = 15h

Divide both sides by 15:

h = 10 hours

3.  4x + 2y = -2

subtract 4x from each side"

2y = -4x - 2

Divide both sides by 2:

y = -4x-2 / 2

y = -2x -1