Answer:
Step-by-step explanation:

Answer:
Demand: q = -50p + 1200
Supply: q = 40p
Step-by-step explanation:
First let's define our variables.
q = quantity of T-shirts
p = price
We know that when p = 12, q = 600. When p increases by 1, q decreases by 50. So this is a line with slope -50 that passes through the point (12, 600). Using point-slope form to write the equation:
q - 600 = -50 (p - 12)
Converting to slope-intercept form:
q - 600 = -50p + 600
q = -50p + 1200
Similarly, we know that when p = 9.75, q = 600 - 210 = 390. When p increases by 1, q increases by 40. So this is a line with slope 40 that passes through the point (9.75, 390). Using point-slope form to write the equation:
q - 390 = 40 (p - 9.75)
Converting to slope-intercept form:
q - 390 = 40p - 390
q = 40p
The equation is true because both sides are identical.
9y^3+8y=4y+18y^2
9y^3-18y^2+4y=0
*Divide the whole thing by y
9y^2-18y+4=0
*use quadratic formula to solve