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3 years ago

Solve the equation 121x2+64=0

Mathematics

1 answer:

olganol [36]3 years ago

4 0

Answer:

x = ± 8i/11

Step-by-step explanation:

121x2+64=0

121x^2 = -64

x^2 = -64/121

x = +/- √(-64/121)

x = +/- 8i/11

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4 years ago

15 POINTS: A motorboat traveling downstream covers the distance between port M and port N in 6 hours. Once, the motorboat stoppe

pav-90 [236]

Answer: S=18

Step-by-step explanation:

D = distance between M and N

S = speed of the boat

S + 2 = speed down streem

S - 2 = speed upstream

T = time on the downstream leg until the boat made its turn

9-T= time on the upstream leg

6(S + 2) = D

T (S + 2) = D - 40

(9-T)(S-2) = D - 40

now we have 3 equations and 3 uknowns

lets multply everything out

6S + 12 = D

ST + 2T = D - 40

9S - 18 - ST + 2T = D - 40

add the second 2 together to get rid of the ST term

9S - 18 + 4T = 2D - 80

and lest subtract them from one annother

2ST - 9S + 18 = 0

if we can find T in terms of S we will have a quadratic equation, and will be able to use the quadratic formula / factor

9S - 18 + 4T = 2(6S + 12) - 80

9S - 18 + 4T = 12 S + 24 - 80

4T = 3S - 38

T = 0.75 S - 9.5

2S(0.75 S - 9.5) - 9S + 18 = 0

1.5 S^2 - 28 S + 18 = 0

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3 years ago

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A 25 ft ladder leans against a building. The ladder’s base is 13.5 feet from the building. Find the angle of elevation, which th

Goryan [66]

Answer:

57.3°

Step-by-step explanation:

A 25 feet ladder leans against a building.

The ladder's base is 13.5 feet from the building.

The ladder, the wall of the building and the ground form a right-angled triangle of:

Hypotenuse = 25 feet

Base = 13.5 feet

We are to find the angle of elevation which the ladder makes with the ground (or rather the angle created by hypotenuse and base)

Let's say the angle = X°

According to a trigonometric equation;

cos X° = adjacent side ÷ hypotenuse = $\frac{13.5}{25}$ = 0.54

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3 years ago