Answer:
500 phones
Step-by-step explanation:
cost of manufacturing: y = 80x + 10,000
money from phone sales: y = 100x
* note: x = #phones
solve for when they're equal;
100x = 80x + 10,000
100x - 80x = 80x - 80x + 10,000
20x = 10,000 –––––––––––> divide both sides by 20
x = 500
B imakes the most sense so I agree it is b
Step-by-step explanation:
Use SOH-CAH-TOA.
Sine = Opposite / Hypotenuse
Cosine = Adjacent / Hypotenuse
Tangent = Opposite / Adjacent
You're given an angle, the adjacent side to that angle, and the hypotenuse. So use cosine.
Cosine = Adjacent / Hypotenuse
cos 37° = 48 / x
Multiply both sides by x.
x cos 37° = 48
Divide both sides by cos 37°.
x = 48 / cos 37°
If desired, use a calculator to evaluate.
x ≈ 60.1
Answer:
x = (-5 ± 2√10) / 3
Step-by-step explanation:
5 − 10x − 3x² = 0
Write in standard form:
-3x² − 10x + 5 = 0
Solve with quadratic formula:
x = [ -b ± √(b² − 4ac) ] / 2a
x = [ -(-10) ± √((-10)² − 4(-3)(5)) ] / 2(-3)
x = [ 10 ± √(100 + 60) ] / -6
x = (10 ± 4√10) / -6
x = (-5 ± 2√10) / 3
