Step-by-step explanation:
Slope-intercept form: y = mx + c
y = x + 3 is already in this form.
3x + 3y = -9,
3y = -3x - 9
y = -x - 3.
Answer:
x = 5/39
, y = 539/39
Step-by-step explanation:
Solve the following system:
{y - 2.5 x = 13.5
12.25 x - y = -12.25
In the first equation, look to solve for y:
{y - 2.5 x = 13.5
12.25 x - y = -12.25
y - 2.5 x = y - (5 x)/2 and 13.5 = 27/2:
y - (5 x)/2 = 27/2
Add (5 x)/2 to both sides:
{y = 1/2 (5 x + 27)
12.25 x - y = -12.25
Substitute y = 1/2 (5 x + 27) into the second equation:
{y = 1/2 (5 x + 27)
1/2 (-5 x - 27) + 12.25 x = -12.25
(-5 x - 27)/2 + 12.25 x = 12.25 x + (-(5 x)/2 - 27/2) = 9.75 x - 27/2:
{y = 1/2 (5 x + 27)
9.75 x - 27/2 = -12.25
In the second equation, look to solve for x:
{y = 1/2 (5 x + 27)
9.75 x - 27/2 = -12.25
9.75 x - 27/2 = (39 x)/4 - 27/2 and -12.25 = -49/4:
(39 x)/4 - 27/2 = -49/4
Add 27/2 to both sides:
{y = 1/2 (5 x + 27)
(39 x)/4 = 5/4
Multiply both sides by 4/39:
{y = 1/2 (5 x + 27)
x = 5/39
Substitute x = 5/39 into the first equation:
{y = 539/39
x = 5/39
Collect results in alphabetical order:
Answer: {x = 5/39
, y = 539/39
dropped $3 means "-3", increased $6 means "+6"
the price dropped twice so 2(-3) and increased once by 6
so, 2(-3) + 6 = 0
the change in price is $0
Here, both numbers are divisible by 7 so that brings you to 9:4
