The correct answer would be: 18+18i
Factor:
3x^2 + 27
= 3(x^2 + 9)
Answer is 3(x^2 + 9), when factored.
A) (3x + 9i)(x + 3i)
= (3x + 9i)(x + 3i)
= (3x)(x) + (3x)(3i) + (9i)(x) + (9i)(3i)
= 3x^2 + 9ix + 9ix + 27i^2
= 27i^2 + 18ix + 3x^2
B) (3x - 9i)(x + 3i)
= (3x + - 9i)(x + 3i)
= (3x)(x) + (3x)(3i) + ( - 9i)(x) + (- 9i)(3i)
= 3x^2 + 9ix - 9ix - 27i^2
= 27i^2 + 3x^2
C) (3x - 6i)(x + 21i)
= (3x + - 6i)(x + 21i)
= (3x)(x) + (3x)(21i) + (- 6i)(x) + ( -6i)(21i)
= 3x^2 + 63ix - 6ix - 126i^2
= - 126i^2 + 57ix + 3x^2
D) (3x - 9i)(x - 3i)
= (3x + - 9)(x + - 3)
= (3x)(x) + (3x)( - 3i) + (- 9)(x) + ( - 9)( - 3i)
= 3x^2 - 9ix - 9x + 27i
= 9ix + 3x^2 + 27i - 9x
Hope that helps!!!
Answer:
x = 387
Step-by-step explanation:
The wind acts in the opposite direction to the plane when the time is longer.
The wind acts in the same direction as the plane when the time is shorter.
Equation
d = r*t
Givens
- d = 1720
- x = plane's speed
- y = wind speed
- t1 = 5 hours
- t2 = 4 hours.
Substitution
- d = (x + y) * t
- 1720 = (x + y) * 4
- 1720 = (x - y) * 5
Since the two distances are the same, you can equate the right hand sides.
- (x + y) * 4 = (x - y)*5 Remove the brackets.
- 4x + 4y = 5x - 5y Add 5y to both sides
- 4x + 4y + 5y = 5x - 5y + 5y Combine all the terms.
- 4x + 9y = 5x Subtract 4x from both sides
- 9y + 4x - 4x = 5x - 4x Combine
- 9y = x
Now use one of the given equations with the distance
- 1720 = (x + y)*4 Substitute 9y for x
- 1720 = (9y + y) * 4 Combine
- 1720 = 10y * 4 Multiply the right
- 1720 = 40y Divide by 40
- 1720/40 = 40y/40 Do the division
- 43 = y y = wind speek
- 9y = x x = 9*y
- 9*43 = x
- x = 387 miles per hour.
Divide both 1 yard and 0.914 meters by 1. 1x = 0.914y
Now, since you want 1 meter = "variable"
1 meter times 1 yard divided by 0.914 meters.
1 meter = 1.094 yards
Answer:
v = 66/7
Step-by-step explanation:
Step 1: Write equation
-7v + 3 = -63
Step 2: Solve for <em>v</em>
<u>Subtract 3 on both sides:</u> -7v = -66
<u>Divide both sides by -7:</u> v = 66/7
Step 3: Check
<em>Plug in x to verify if it's a solution.</em>
-7(66/7) + 3 = -63
-66 + 3 = -63
-63 = -63
