Answer:
1. Slope: -3/4
2. Point-slope: y+4=-3/4(x+4)
3. Slope-intercept: y=-3/4x-7
4. Standard form: 3x+4y=-28
Step-by-step explanation:
1. To find the slope, use the slope formula, which is: y2-y1/x2-x1.
Plug the y-coordinates into the top part of the equation and the x-coordinates into the bottom part.
2--4/-4-4
2+4/-8 = 6/-8, or 3/-4
2. Use the slope and one of the x and y coordinates to put the equation into point-slope form. Recall that point-slope form is: y-y1=m(x-x1). Let's use the coordinates (4,-4).
y+4=-3/4(x+4)
3. To put the point-slope equation into slope-intercept form (y=mx+b), you need to distribute -3/4 to x+4 and subtract 4 from both sides.
When you distribute, the equation becomes:
y+4=-3/4x-3
Finally, when you subtract 4, the equation becomes:
y=-3/4x-7
4. Standard form is written as x+y= #.
To convert y=mx+b to standard form, first subtract -3/4x from both sides.
-3/4x + y = -7
Multiply everything by 4
3x + 4y = -28
So if you take 10% of $19.50, you have $1.95. If you multiply $1.95 by 6, you get $11.70 which is 60% of the original cost of the book. Add $11.70 to $19.50 and you have $31.20.
Simplify 7x + 2y = -23
Solving
7x + 2y = -23
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-2y' to each side of the equation.
7x + 2y + -2y = -23 + -2y
Combine like terms: 2y + -2y = 0
7x + 0 = -23 + -2y
7x = -23 + -2y
Divide each side by '7'.
x = -3.285714286 + -0.2857142857y
Simplifying
x = -3.285714286 + -0.2857142857y
