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3 years ago

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Mathematics

1 answer:

Alecsey [184]3 years ago

4 0

Answers:

R = -3
S = -3
T = -9

For each row, you're adding the values of 'a' and 'b'. The first row has 1+2 = 3.

When adding two negatives, add the positive versions of each number, then make the result negative. So -1 + (-2) can be thought of as 1+2 = 3, then you make everything negative.

When adding a negative to a positive, you'll subtract the positive version of each number. The final result is positive if the larger absolute value is positive, or otherwise it's negative. We have -4+1 that can be thought of as 4-1 = 3, but since the '4' is larger and it is negative, this means -4+1 = -3.

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Bill and Eugene left the airport at the same time. They traveled in opposite directions. Eugene traveled 21.1 km/h faster than B

gizmo_the_mogwai [7]

Answer:

56.3 kilometers per hour

Step-by-step explanation:

We know D = RT

where

D is distance

R is rate (speed)

T is time

Let's Bill's rate be "x". Thus using equation we can write:

D = xt

We know Eugene travelled 21.1 faster than Bill, so Eugene's rate is 21.1 + x. So we can write:

D = (21.1 + x)t

D = 21.1t + xt

Now, putting t = 1 in both since after 1 hour given, we have:

D = x(1)

D = x

and

D = 21.1(1) + x(1)

D = 21.1 + x

We know the sum of both the distance is 133.7, so we can write:

x + 21.1 + x = 133.7

Solving for x:

2x = 133.7 - 21.1

2x = 112.6

x = 112.6 / 2

x = 56.3 km/hr

This is Bill's rate: 56.3 kilometers per hour

8 0

3 years ago

How do you simplify <img src="https://tex.z-dn.net/?f=%5Cfrac%7B%5Csqrt%7B2%7D%20%2B%5Csqrt%7B6%7D%20%7D%7B%5Csqrt%7B8%7D%20%2B%

blondinia [14]

The trick is to exploit the difference of squares formula,

$a^2-b^2=(a-b)(a+b)$

Set a = √8 and b = √6, so that a + b is the expression in the denominator. Multiply by its conjugate a - b:

$(\sqrt8+\sqrt6)(\sqrt8-\sqrt6)=(\sqrt8)^2-(\sqrt6)^2=8-6=2$

Whatever you do to the denominator, you have to do to the numerator too. So

$\dfrac{\sqrt2+\sqrt6}{\sqrt8+\sqrt6}=\dfrac{(\sqrt2+\sqrt6)(\sqrt8-\sqrt6)}{(\sqrt8+\sqrt6)(\sqrt8-\sqrt6)}=\dfrac{(\sqrt2+\sqrt6)(\sqrt8-\sqrt6)}2$

Expand the numerator:

$(\sqrt2+\sqrt6)(\sqrt8-\sqrt6)=\sqrt{2\cdot8}+\sqrt{6\cdot8}-\sqrt{2\cdot6}-(\sqrt6)^2$

$(\sqrt2+\sqrt6)(\sqrt8-\sqrt6)=\sqrt{16}+\sqrt{48}-\sqrt{12}-6$

$(\sqrt2+\sqrt6)(\sqrt8-\sqrt6)=4+\sqrt{48}-\sqrt{12}-6$

$(\sqrt2+\sqrt6)(\sqrt8-\sqrt6)=-2+\sqrt{12}(\sqrt4-1)$

$(\sqrt2+\sqrt6)(\sqrt8-\sqrt6)=-2+\sqrt{12}(2-1)$

$(\sqrt2+\sqrt6)(\sqrt8-\sqrt6}=-2-\sqrt{12}$

So we have

$\dfrac{\sqrt2+\sqrt6}{\sqrt8+\sqrt6}=-\dfrac{2+\sqrt{12}}2$

But √12 = √(3•4) = 2√3, so

$\dfrac{\sqrt2+\sqrt6}{\sqrt8+\sqrt6}=-\dfrac{2+2\sqrt3}2=\boxed{-1-\sqrt3}$

7 0

3 years ago

2x + 8 = 3x + x + 18<br> how do i solve this

Gnoma [55]

Answer:

x=-10

Step-by-step explanation:

reorder the terms: 8+2x=18+3x

solve: 8+2x=18+3x

-3x -3x

_________

8-1x=18

-8. -8

________

-1x= 10

__ __

-1 -1

________

<u>x= -10</u>

3 0

3 years ago

Molly wrote a computer program that generates two random numbers between one and 10. When she runs it, what is the probability t

Igoryamba

Answer:

Step-by-step explanation:

The accepted values are 2 3 4 5 6 One is not counted. It says between.

The total number of ways each dice can be thrown is 2 3 4 5 6 7 8 9 Ten is not counted. Same reason.

5/8 * 5/8 = 25/64 = 0.39

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3 years ago

Find the axis of symmetry of the graph of y=x^2+2x-4

Ludmilka [50]

X = -1
(-1, -5) The line is horizontal.
:) <span />

6 0

4 years ago