No, because 7 x 21 is 147.
- 8x - 9 = - 21
Add 9 to both sides:
- 8x = - 12
Divide both sides by - 8:
x = -12/-8
x = -3/-2
x = 3/2 OR 1.5
Hope this answer helps :)
Answer:
Minimum average cost = 743.75
Number of dvds to achieve the cost = 62.5
Step-by-step explanation:
Given the cost equation
C = 0.04x² − 5x + 900
To Obtian the minimum average cost ;
Find dc/dx = 0
Diffentiate cost, c it ith respect to x
dc/dx = 2(0.04x) - 5
dc/dx = 0.08x - 5 = 0
0.08x = 5
x = 5 / 0.08
x = 62.5
Substitute the value of x into C to obtain the minimum average cost
C = 0.04(62.5)² - 5(62.5) + 900
C = 743.75
Let's call the missing angles Q, R, and S. We know that Q = 2R and S = R - 8 and we also know that Q + R + S = 180. So that really just means that 180 = 4R - 8 Add 8 on both sides of the equal sign
188 = 4R So we divide on both sides of the equal sign by 4
47 = R And that means that Q = 2 * 47 So Q = 94 and S = 47 - 8 So S = 39
39 + 94 + 47 = 180
The missing angles are 39 degrees 94 degrees and 47 degrees.