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3 years ago

1)Evaluate 2A - 3B for A = 7 and B = -2.

1 answer:

5 0

Hey Brion,

1) Evaluate 2A - 3B for A = 7 and B = -2.
To solve this start by filling in the variables.
2(7) - 3(-2)

Now multiply, remember that a positive times a negative is a negative.
14 - (-6)

Finally, subtract. Remember, Keep, Change, Change (KCC). Keep the first number, change symbol (for subtraction use addition), and change the negative number to a positive number.
14 + 6 = 20

2) If x = -3, then x 2-7x + 10 equals
Start by filling in the variables.
-3(2) - 7(-3) + 10

Now follow PEMDAS (Parentheses, Exponents, Multiplication & Division, Addition & Subtraction) to solve. Remember K.C.C (no. 1 above)
-3(2) - 7(-3) + 10
(-6) - (-21) + 10
(-6) + (21) + 10
15 + 10
25*****See NOTE!***
_____________________________________________________________
Note: For #2 you may be missing a symbol between the first "x" and "2" because the answer I got above (25) is not one of your choices. Let me know what symbol is missing in the equation: x 2-7x + 10, and I will help you solve it.

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What is the inverse of f(x) = -5x - 8?

grin007 [14]

Answer:

y=-1/5x-9/5

Step-by-step explanation:

y=-5x-9

x=-5y-9

-5y=x+9

y=-1/5x+9/-5

y=-1/5x-9/5

8 0

3 years ago

Solve the system by using a matrix equation (Picture provided)

Katyanochek1 [597]

Answer:

Option b is correct (8,13).

Step-by-step explanation:

7x - 4y = 4

10x - 6y =2

it can be represented in matrix form as $\left[\begin{array}{cc}7&-4\\10&-6\end{array}\right] \left[\begin{array}{c}x\\y\end{array}\right] = \left[\begin{array}{c}4\\2\end{array}\right]$

A= $\left[\begin{array}{cc}7&-4\\10&-6\end{array}\right]$

X= $\left[\begin{array}{c}x\\y\end{array}\right]$

B= $\left[\begin{array}{c}4\\2\end{array}\right]$

i.e, AX=B

or X= A⁻¹ B

A⁻¹ = 1/|A| * Adj A

determinant of A = |A|= (7*-6) - (-4*10)

= (-42)-(-40)

= (-42) + 40 = -2

so, |A| = -2

Adj A= $\left[\begin{array}{cc}-6&4\\-10&7\end{array}\right]$

A⁻¹ = $\left[\begin{array}{cc}-6&4\\-10&7\end{array}\right]$ / -2

A⁻¹ = $\left[\begin{array}{cc}3&-2\\5&-7/2\end{array}\right]$

X= A⁻¹ B

X= $\left[\begin{array}{cc}3&-2\\5&-7/2\end{array}\right] *\left[\begin{array}{c}4\\2\end{array}\right]$

X= $\left[\begin{array}{c}(3*4) + (-2*2)\\(5*4) + (-7/2*2)\end{array}\right]$

X= $\left[\begin{array}{c}12-4\\20-7\end{array}\right]$

X= $\left[\begin{array}{c}8\\13\end{array}\right]$

x= 8, y= 13

solution set= (8,13).

Option b is correct.

3 0

3 years ago

Help a sister out :))

soldi70 [24.7K]

Answer:

125

Step-by-step explanation:

-125 x -1

5 0

3 years ago

A recipe says it produced the best sweet tea. In addition to using tea bags, the recipe calls for ½ cup of sugar for every 1 ½ c

Sergio [31]

Answer:

The relationship between the number of cups of water and sugar in the recipe is w = ¹/₃(s)

Step-by-step explanation:

Given;

number of cups of sugar = s

number of cups of water = w

The relationship between the number of cups of water and sugar in this recipe is given as;

½ cup of sugar is proportional to 1 ½ cups of water

$\frac{1}{2} s = \frac{3}{2}w\\\\s= 3w\\\\w = \frac{s}{3}$

Therefore, the relationship between the number of cups of water and sugar in the recipe is w = ¹/₃(s)

7 0

2 years ago

Read 2 more answers

Line segment AB is shown on a coordinate grid: A coordinate grid is shown from positive 6 to negative 6 on the x-axis and from p

serious [3.7K]

Answer:

A′B′ and AB are equal in length.

Step-by-step explanation:

Given that the location of the points are at A(1, 3) and B(5, 3).

Transformation is the movement of a point from its initial location to a new location. Types of transformation are reflection, rotation, translation and dilation.

Rigid transformation are transformation that preserves the shape and size when performed. Types of rigid transformation are reflection, rotation, translation.

Hence if AB is rotated 270 degrees counterclockwise about the origin to form A′B′, both A′B′ and AB are equal in length because rotation is a rigid transformation.

If A(x,y) is rotated 270 degrees counterclockwise about the origin, it becomes A'(y,-x).

Hence if AB is rotated 270 degrees counterclockwise about the origin to form A'(3, -1), B'(3, -5)

$AB=\sqrt{(5-1)^2+(3-3)^2} =4\\\\A'B'=\sqrt{(3-3)^2+(-5-(-1))^2}=4,$

5 0

3 years ago