Answer:
57x = 1311
x = 23 hours
Step-by-step explanation:
I don't know how you would model this with two equations but the answer is 23 hours.
Question:
What are the solution(s) to the quadratic equation 50 – x2 = 0?
A) x = ±2Plus or minus 2 StartRoot 5 EndRoot
B) x = ±6Plus or minus 6 StartRoot 3 EndRoot
C) x = ±5Plus or minus 5 StartRoot 2 EndRoot
D) no real solution
Answer:
C) x = ±5Plus or minus 5 StartRoot 2 EndRoot
Jake spent a total of 70 cents.
b = black-and-white = 8 cents
c = color = 15 cents
70 = 8b + 15c
he made a total of 7 copies
b + c = 7
system of equation:
70 = 8b + 15c
b + c = 7
--------------------------
b + c = 7
b + c (-c) = 7 (-c)
b = 7 - c
plug in 7 - c for b
70 = 8(7 - c) + 15c
Distribute the 8 to both 7 and - c (distributive property)
70 = 56 - 8c + 15c
Simplify like terms
70 = 56 - 8c + 15c
70 = 56 + 7c
Isolate the c, do the opposite of PEMDAS: Subtract 56 from both sides
70 (-56) = 56 (-56) + 7c
14 = 7c
divide 7 from both sides to isolate the c
14 = 7c
14/7 = 7c/7
c = 14/7
c = 2
c = 2
---------------
Now that you know what c equals (c = 2), plug in 2 for c in one of the equations.
b + c = 7
c = 2
<em>b + (2) = 7
</em><em />Find b by isolating it. subtract 2 from both sides
b + 2 = 7
b + 2 (-2) = 7 (-2)
b = 7 - 2
b = 5
Jake made 5 black-and-white copies, and 2 color copies
hope this helps
