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3 years ago

A system of equations is shown:

Mathematics

1 answer:

Harrizon [31]3 years ago

6 0

Answer:

Step-by-step explanation:

$\left\{\begin{array}{ccc}2x=-y+6&(1)\\-4x+3y=8&(2)\end{array}\right\\\\(1)\\-y+6=2x\qquad\text{subtract 6 from both sides}\\-y=2x-6\qquad\text{change the signs}\\y=6-2x\\\\\text{substitute it to (2):}\\\\(2)\\-4x+3(6-2x)=8\qquad\text{use the distributive property}\\-4x+(3)(6)+(3)(-2x)=8\\-4x+18-6x=8\qquad\text{subtract 18 from both sides}\\-10x=-10\qquad\text{divide both sides by (-10)}\\x=1\\\\\text{put the value of x to (1):}\\\\y=6-2(1)\\y=6-2\\y=4$

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Which of the following is equivalent to (n-3)(n-5) a. n2-8n+15, b. n2+8n-15, c. n2-15n+8

solong [7]

Foil the binomials

First: n*n=n^2
Outer: n*-5=-5n
Inner: -3*n=-3n
Last: -3*-5=15

Put it together and simplify
n^2-5n-3n+15
n^2-8n+15

Final answer: A

5 0

3 years ago

1. How many degrees is x .x 41 82 20.5 o 41 О 10

Alja [10]

Answer:

Option (1)

Step-by-step explanation:

By the inscribed angle theorem inside a circle,

"Measure of an inscribed angle is half the measure of the intercepted arc"

$\frac{1}{2}$ [m(arc AB)] = m(∠ABC)

m(arc AB) = 2[m(∠ABC)]

x = 2(41°)

x = 82°

Option (1) is the correct option.

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2 years ago

Pls help :) i really need to finish it

Licemer1 [7]

Answer:

ok so if equilateral triangle has 1 inch and box has 9 inch of height, the lateral area would be 27 square-inch

Step-by-step explanation:

5 0

2 years ago

Show work please. solve system of equations using matrices.

nadya68 [22]

Answer:

(t, t -1, t)

Step-by-step explanation:

You have three unknowns but only 2 equations, so you can't really SOLVE this...you can get a solution with a variable still in it (I forget what this is called. I think it refers to infinite many solutions). Here's how it works:

Set up your matrix:

$\left[\begin{array}{ccc}1&-2&1\\2&-1&-1\\\end{array}\right] \left[\begin{array}{ccc}2\\1\\\end{array}\right]$

You want to change the number in position 21 (the 2 in the scond row) to a 0 so you have y and z left. Do this by multiplying the top row by -2 then adding it to the second row to get that 2 to become a 0. Multiplying in a -2 to the top row gives you:

$\left[\begin{array}{ccc}-2&4&-2\\2&-1&-1\\\end{array}\right]\left[\begin{array}{ccc}-4\\1\\\end{array}\right]$

Then add, keeping the first row the same and changing the second to reflect the addition:

$\left[\begin{array}{ccc}-2&4&-2\\0&3&-3\\\end{array}\right] \left[\begin{array}{ccc}-4\\-3\\\end{array}\right]$

The second equation is this now:

3y - 3z = -3. Solving for y gives you y = z - 1. Let's let z = t (some random real number that will make the system true. Any number will work. I'll show you at the end. Just bear with me...)

lf z = t, and if y = z - 1, then y = t - 1. So far we have that y = t - 1 and z = t. Now we solve for x:

From the first equation in the original system,

x - 2y + z = 2. Subbing in t - 1 for y and t for z:

x - 2(t - 1) + t = 2. Simplify to get

x - 2t + 2 + t = 2 and x - t = 0, and x = t. So the solution set is (t, t - 1, t). Picking a random value for t of, let's say 2, sub that in and make sure it works. If:

x - 2y + z = 2, then t - 2(t - 1) + t = 2 becomes t - 2t + 2 + t = 2, and with t = 2, 2 - 2(2) + 2 + 2 = 2. Check it: 2 - 4 + 4 = 2 and 2 = 2. You could pick any value for t and it will work.

6 0

3 years ago

The Better Baby Buggy Co. has just come out with a new model, the Turbo. The market research department predicts that the demand

dlinn [17]

Answer:

$68

Step-by-step explanation:

We have been given the demand equation for Turbos as $q=-4p+544$ , where q is the number of buggies the company can sell in a month if the price is $p per buggy.