Given that e= 2i – 5j + 9k and f= 8i + 15j + k, find 3f – 2e.

Mathematics

2 answers:

ipn [44]3 years ago

5 0

Plug in "8i + 15j + k" for "f", and "2i – 5j + 9k" for "e"

3(8i + 15j + k) - 2(2i – 5j + 9k)

Distribute 3 to (8i + 15j + k) & - 2 to (2i – 5j + 9k)

3(8i + 15j + k) = 24i + 45j + 3k

-2(2i - 5j + 9k) = -4i + 10j - 18k

-------------------------------------------------------------------------------------------------------------------

Simplify. Combine like terms

24i - 4i + 45j + 10j + 3k - 18k

(24i - 4i) + (45j + 10j) + (3k - 18k)

20i + 55j - 15k is your answer, or (C)

-------------------------------------------------------------------------------------------------------------------

hope this helps

dmitriy555 [2]3 years ago

3 0

3f – 2e

Plug in 2i – 5j + 9k for e and 8i + 15j + k for f

3(8i + 15j + k) - 2(2i – 5j + 9k)

Distribute 3 and 2 inside their respective parentheses

(24i + 45j + 3k) - (4i - 10j + 18k)

Now distribute -1 (negative sign) inside the parentheses on the right

(24i + 45j + 3k) - 4i + 10j - 18k

Combine like terms

20i + 55j - 15k is your answer (third choice down)

You might be interested in

HELP NOW!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!11 Water boils at 212 degrees __________ A. Ce

34kurt

<span>alright it would have been easier if u took a pic but i think its a matching prob with choices A thro F:

Water boils at 212 degrees __________

A. Celsius Incorrect

Water boils at 100 degrees _________

B. Kelvin Incorrect

Water boils at 373 _______

C. Thermal Equilibrium Incorrect

Temperature at which all kinetic energy stops

D. Thermal Energy Incorrect

Reached when 2 objects have the same temperature

E. Absolute zero Incorrect

Sum of all kinetic energy and potential energy in an object's particles

F. Fahrenheit

So here are the correct matches:

</span>Water boils at 212 degrees __________F. Fahrenheit

Water boils at 100 degrees _________ A. Celsius

Water boils at 373 _______ B. Kelvin

Temperature at which all kinetic energy stops______E. Absolute zero

Reached when 2 objects have the same temperature ________C. Thermal Equilibrium

Sum of all kinetic energy and potential energy in an object's particles _____ D. Thermal Energy

7 0

3 years ago

Triangle DEF has vertices D(−4, 1), E(2, 3), and F(2, 1) and is dilated by a factor of 3 using the point (1, 1) as the point of

CaHeK987 [17]

Answer: $D'(-14,1);\ E'(4,7);\ F'(4,1)$

Step-by-step explanation:

Since the center of dilation is not at the origin, we can use the following formula in order to find the coordinates of the vertices of the triangle D'E'F':

$D_{O,k}(x,y)=(k(x-a)+a, k(y-b)+b)$