Answer:
32
Step-by-step explanation:
77 quarters and dimes
q + d = 77
subtract q from both sides
d = 77 - q
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A collection of quarters and dimes is worth $12.50 (1250 cents)
25q + 10d = 1250
substitute for d
25q + 10(77 - q) = 1250
distribute
25q + 770 - 10q = 1250
Combine like terms
15q + 770 = 1250
subtract 770 from both sides
15q = 480
divide both sides by 15
q = 32
You need to know the value of X to determine whether or not the equation is true.
Answer:
cosine = adjacent / hypotenuse
cosine 62º = JL / 17
JL = cosine 62º * 17
JL = .47 * 17
JL = 7.99
JL = 8.0
Step-by-step explanation:
Answer:
Her speed on the summit was 35 mph.
Step-by-step explanation:
Her speed on the summit was "x" mph while her speed while climbing was "x - 10" mph. The distance she rode uphill was 55 miles and on the summit it was 28 miles. The total time she explored the mountain was 3 hours. Therefore:
time uphill = distance uphill / speed uphill = 55 / (x - 10)
time summit = distance summit / speed summit = 28 / x
total time = time uphill + time summit
3 = [55 / (x - 10)] + 28 / x
3 = [55*x + 28*(x - 10)]/[x*(x - 10)]
3*x*(x - 10) = 55*x + 28*x - 280
3x² - 30*x = 83*x - 280
3x² - 113*x + 280 = 0
x1 = {-(-113) + sqrt[(-113)² - 4*(3)*(280)]}/(2*3) = 35 mph
x2 = {-(-113) - sqrt[(-113)² - 4*(3)*(280)]}/(2*3) = 2.67 mph
Since her speed on the uphill couldn't be negative the speed on the summit can only be 35 mph.
The answer to this is Y = 1