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2 years ago

How can I use models to multiply fractions

2 answers:

8 0

Say we have 1/2 * 1/2. Make a square and cut it in half vertically. Shade one of the halves. Then, cut the square horizontally and shade in half of the shaded area. There we go!

denis-greek [22]2 years ago

7 0

You can count the numbers shaded over the total numbers in the model

You might be interested in

Factor −1/4 out of −1/2x−5/4y. The factored expression is .

Olegator [25]

Answer:

(-1/4)(2x +5y)

Step-by-step explanation:

Multiply and divide by -1/4:

$-\frac{1}{2}x-\frac{5}{4}y=\dfrac{(-\frac{1}{4})(-\frac{1}{2}x-\frac{5}{4}y)}{-\frac{1}{4}}=\left(-\dfrac{1}{4}\right)(-4)\left(-\dfrac{1}{2}x-\dfrac{5}{4}y\right)\\\\=\left(-\dfrac{1}{4}\right)\left(2x+5y)$

7 0

3 years ago

Write one pair of brackets in this calculation so that the answer is correct. 5 + 2 × 7 – 4 = 11

BartSMP [9]

Answer:

$5+2*(7-4) =11$

Step-by-step explanation:

This expression was kind of trial and error for me seeing as I'm not really good at logic, but this is pretty basic. There are three possible places the parentheses can be placed (assuming each pair holds 2 terms);

$(5+2)*7-4\\5+(2*7)-4\\5+2*(7-4)$

The answer to the first expression would be 45, which is not equal to 11.

The answer to the second expression would be 15, which is also not equal to 11.

The answer to the last expression is 11, so that is the correct answer.

Hope this helped :D

- Shay

5 0

3 years ago

Determine which of the lines are parallel and which of the lines are perpendicular. Select all of the statements that are true.

slega [8]

Answers:

Line A is parallel to line D.

Line A is perpendicular to line C.

Line C is perpendicular to line D.

=====================================================

Explanation:

Let's use the slope formula to calculate the slope of the line through (-1,-17) and (3,11)

$(x_1,y_1) = (-1,-17) \text{ and } (x_2,y_2) = (3,11)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{11 - (-17)}{3 - (-1)}\\\\m = \frac{11 + 17}{3 + 1}\\\\m = \frac{28}{4}\\\\m = 7\\\\$

The slope of line A is 7

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

Now let's find the slope of line B.

$(x_1,y_1) = (0,4) \text{ and } (x_2,y_2) = (7,-5)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{-5 - 4}{7 - 0}\\\\m = -\frac{9}{7}\\\\$

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

Now onto line C.

$(x_1,y_1) = (7,1) \text{ and } (x_2,y_2) = (0,2)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{2 - 1}{0 - 7}\\\\m = \frac{1}{-7}\\\\m = -\frac{1}{7}\\\\$

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

Lastly we have line D.

$(x_1,y_1) = (-1,-6) \text{ and } (x_2,y_2) = (1,8)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{8 - (-6)}{1 - (-1)}\\\\m = \frac{8 + 6}{1 + 1}\\\\m = \frac{14}{2}\\\\m = 7\\\\$

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

Here's a summary of the slopes we found

$\begin{array}{|c|c|} \cline{1-2}\text{Line} & \text{Slope}\\\cline{1-2}\text{A} & 7\\\cline{1-2}\text{B} & -9/7\\\cline{1-2}\text{C} & -1/7\\\cline{1-2}\text{D} & 7\\\cline{1-2}\end{array}$

Recall that parallel lines have equal slopes, but different y intercepts. This fact makes Line A parallel to line D.

Lines A and C are perpendicular to one another, because the slopes 7 and -1/7 multiply to -1. In other words, -1/7 is the negative reciprocal of 7, and vice versa. These two lines form a 90 degree angle.

Lines C and D are perpendicular for the same reasoning as the previous paragraph.

Line B unfortunately is neither parallel nor perpendicular to any of the other lines mentioned.

You can use a graphing tool like Desmos or GeoGebra to verify these answers.

6 0

1 year ago

Evaluate the variable expression when a = 5, b = 5, and c = -4.<br> Bc divided by (2a)

zlopas [31]

Answer:

-2

Step-by-step explanation:

Bc÷2a

5×-4÷2×5

-20÷10

-2

6 0

3 years ago

Read 2 more answers

The graph of the function C(x) = −0.34x2 + 12x + 62 is shown. The function models the production cost, C, in thousands of dollar

Virty [35]

Answer:

0 ≤ x < 1.12 and 34.18 < x ≤ 39.87

Step-by-step explanation:

Let

x ----> is the number of tires produced, in thousands

C(x) ---> the production cost, in thousands of dollars

we have

$C(x)=-0.34x^{2} +12x+62$

This is a vertical parabola open downward (the leading coefficient is negative)

The vertex represent a maximum

The graph in the attached figure

we know that

Looking at the graph

For the interval [0,1.12) -----> $0\leq x$

The value of C(x) ----> $C(x) < 75$

That means ----> The production cost is under $75,000

For the interval (34.18,39.87] -----> $34.18 < x\leq 39.87$

The value of C(x) ----> $C(x) < 75$

That means ----> The production cost is under $75,000

Remember that the variable x (number of tires) cannot be a negative number

therefore

If the company wants to keep its production costs under $75,000 a reasonable domain for the constraint x is

0 ≤ x < 1.12 and 34.18 < x ≤ 39.87

7 0

3 years ago