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2 years ago

Jim is showing his work in simplifying (−8.5 + 6.1) − 1.3.

Mathematics

1 answer:

dexar [7]2 years ago

8 0

9514 1404 393

Answer:

In step 4, Jim's answer is incorrect.

Step-by-step explanation:

In step 1, Jim swaps the order of addends using the commutative property of addition.

In step 2, Jim uses the distributive property to factor -1 from the final two terms. (The associative property lets Jim move parentheses.)

6.1 +(-8.5 -1.3) . . . associative property

6.1 +(-1)(8.5 +1.3) . . . distributive property

In step 3, Jim has used the properties of real numbers to form the sum of two of them.

In step 4, Jim wrote an answer of 1.1, when the answer should have been -3.7. Jim's answer is incorrect.

The descriptive statements about steps 2 and 4 are both true.

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What is the value of fraction 1 over 3x3 + 5.2y when x = 3 and y = 2?

Slav-nsk [51]

Hello from MrBillDoesMath!

Answer:

1/ 91.4

Discussion:

Evaluate 1/ ( 3x^3 + 5.2y) when x = 3, y = 2.

1/ (3 (3)^3 + 5.2(2)) =

1/ ( 3 * 27 + 10.4) =

1/ ( 81 + 10.4) =

1/ (91.4) =

.0109 (approx)

Thank you,

MrB

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3 years ago

What’s the midpoint of the line segment joining A and B<br><br> A(2,-5);B(6,1)

IRISSAK [1]

$\bf ~~~~~~~~~~~~\textit{middle point of 2 points } \\\\ A(\stackrel{x_1}{2}~,~\stackrel{y_1}{-5})\qquad B(\stackrel{x_2}{6}~,~\stackrel{y_2}{1}) \qquad \left(\cfrac{ x_2 + x_1}{2}~~~ ,~~~ \cfrac{ y_2 + y_1}{2} \right) \\\\\\ \left( \cfrac{6+2}{2}~~,~~\cfrac{1-5}{2} \right)\implies \left( \cfrac{8}{4}~,~\cfrac{-4}{2} \right)\implies (4,-2)$

7 0

2 years ago

a cell phone battery uses 1/3 of its charge in 3/8 of a day. How much charge will it use in one day?

brilliants [131]

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3 0

2 years ago

x^2-y=7 and y-5x=-11 The system of equations above has two solutions. The solution in Quadrant 1 is (A,B) and the solution in Qu

dimaraw [331]

By solving the system of equations, we can see that the solutions are:

(A, B) = (4, 9)

(C, D) = (1, -6).

<h3>How to solve the system of equations?</h3>

Here we have the following system of equations:

x^2 - y = 7

y - 5x = -11

If we isolate the variable y in both equations, we get:

y = x^2 - 7

y = -11 + 5x

Now we can equate these two to get:

x^2 - 7 = -11 + 5x

now we have a quadratic equation, this can be rewritten as:

x^2 - 7 + 11 - 5x = 0

x^2 - 5x + 4 = 0

Using the quadratic formula, we will see that the solutions are:

$x = \frac{5 \pm \sqrt{(-5)^2 - 4*1*(4)} }{2*1}$

Solving that we get:

$x = \frac{5 \pm \sqrt{(9} }{2} \\\\x = \frac{5 \pm 3}{2}$

So the two solutions for x are:

x = (5 + 3)/2 = 4

x = (5 - 3)/2 = 1

Evaluating the second equation in these x-values we get:

y = -11 + 5*4 = -11 + 20 = 9

y = -11 + 5*1 = -6

Then we have the coordinate pairs: (4, 9) (on the first quadrant) and (1, -6) on the fourth quadrant.

Learn more about systems of equations:

brainly.com/question/13729904

#SPJ1

8 0

6 months ago

The population of a community is known to increase at a rate proportional to the number of people present at time t. The initial

maks197457 [2]

Answer:

The initial population P0 is 7500

Step-by-step explanation:

First of all, we are told that the population is proportional to time. This means that as time goes by, the population will increase. This type of relationship between two variables has the form of a linear equation expressed as:

y = mx + b,

where m is the slope of the curve and b is the intercept of it.

In this case we can state the following equation:

P = mt + P0

Where P is the population at a certain time "t", "m" is the slope of the curve, "t" is the time (this is the independent variable) and P0 is the intercept of the curve and represents the initial population.

Once we state the equation, let's see what we know:

If t = 0, then P = P0

If t = 3, then P = 12000 just as we are told

and if t = 5, then P = 2 P0 because after five years the population has doubled compared to the initial population (P0).

From the definition of the slope of the curve:

(Y2 - Y1)/(X2-X1) = m

and using the data described before we can formulate the slope value:

m = (2P0 - P0)/(5-0)

m = (2P0 - P0)/5

m = P0/5

Then, let's replace the value of m in the following equation:

P = mt + P0

12000 = (P0/5) × 3 + P0 → This is the equation presented when 3 years has gone by and we now have a population of 12000.

12000 = (3/5) P0 + P0

12000 = (8/5) P0

12000×5/8 = P0 = 7500

Then we can calculate the value of the slope m:

m = P0/5

m = 7500/5 = 1500

Now, knowing the value of m and the initial population P0 we are able to calculate the population at any value of "t".

6 0

2 years ago