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aksik [14]
3 years ago
13

Evaluate the determinate of the matrix with work shown.

Mathematics
1 answer:
Leya [2.2K]3 years ago
3 0

1. Divide the first row by -4

(1, -5/4, -3/2)

2. Multiply the first row by -2

(-2, 5/2, 3)

3. Subtract the first row from the third row and restore it.

1 (1, -5/4, -3/2)

3 (0, -15/2, 1)

4. Restore the first row to the original view

(-4, 5, 6)

5. Divide the second row by 4

(0, 1, 1)

6. Multiply the second row by -15/2

(0, -15/2, -15/2)

7. Subtract the second row from the third row and restore it

2 (0, 1, 1)

3 (0, 0, 17/2)

8. Restore the second row to the original view

(0, 4, 4)

9. Multiply the main diagonal elements

-4 x 4 x 17/2 = 136

Answer: Δ = 136

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olga2289 [7]
-5(x+7)<-10.
You need to use the distributive property.
-5x - 35 < -10.
You need to cancel out -35, so you add it to itself, & -10.
-5x < 25.
You need to divide -5 by itself & 25.
x>-5.
3 0
3 years ago
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Please let me know the correct answer.
NNADVOKAT [17]

Set h to 640 and solve for t:

640 = -490t^2 + 1120t

Subtract 640 from both sides:

-490t^2 + 1120t - 640 = 0

The formula to solve a quadratic equation is:

x = -b -/+ sqrtroot (b^2-4ac)/(2a) where a = -490, b = 1120 and c = -640

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x = -1120 -/+ sqrtroot (1120^2-4(-490)(-640) )/ 2(-490)

x = 8/7 = 1.1428 = 1.14

Time was 1.14 seconds

4 0
3 years ago
Write a phrase for EACH expression: <br><br> 10y<br><br> x - 3<br><br> 12n
olga2289 [7]
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Two streets bounding your triangular lot make an angle of 74∘. The lengths of the two sides of the lot on these streets are 126
ycow [4]

Answer: a) Yes, there is enough fance

b) 58.1° and 47.9°

c) The city will not approve, because 1/3 of the area is just 2220.5ft²

Step-by-step explanation:

a) using law of cosines: x is the side we do not know.

x² = 126² + 110² - 2.126.110.cos74°

x² = 20335.3

x = 142.6 ft

So 150 > 142.6, there is enough fance

b) using law of sine:

sin 74/ 142.6 = sinα/126 = sinβ/110

sin 74/ 142.6 = sinα/126

0.006741 = sinα/126

sinα = 0.849

α = sin⁻¹(0.849)

α = 58.1°

sin 74/ 142.6 = sinβ/110

sin 74/ 142.6 = sinβ/110

0.006741 = sinβ/110

sinβ = 0.741

β = sin⁻¹(0.741)

β = 47.9°

Checking: 74+58.1+47.9 = 180° ok

c) Using Heron A² = p(p-a)(p-b)(p-c)

p = a+b+c/2

p=126+110+142.6/2

p=189.3

A² = 189.3(189.3-126)(189.3-110)(189.3-142.6)

A = 6661.5 ft²

1/3 A = 2220.5

So 2300 >  2220.5. The area you want to build is bigger than the area available.

The city will not approve

7 0
3 years ago
Why do both ways of writing the numbers as ten and ones describe the same number?
fiasKO [112]

its just the form of counting and not necessarily the different number
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