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2 years ago

What two numbers' sum=-4 and product=-2

Mathematics

1 answer:

n200080 [17]2 years ago

7 0

Let a and b be the two numbers. Then

a + b = -4

a b = -2

Solve the second equation for b :

b = -2/a

Substitute this into the first equation:

a - 2/a = -4

Multiply both sides by a :

a² - 2 = -4a

Move 4a to the left side:

a² + 4a - 2 = 0

Use the quadratic formula to solve for a :

a = (-4 ± √(4² - 4(-2))) / 2

a = -2 ± √6

If a = -2 + √6, then

-2 + √6 + b = -4

b = -2 - √6

In the other case, we end up with the same numbers, but a and b are swapped.

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3x-5y= 4 -2x + 6у = 18

dezoksy [38]

(57/4, 31/4)

This was using system of equations

5 0

1 year ago

Write an equation for the translation of y=|x|. 2 units down.

Bezzdna [24]

B. Y = |x| - 2
when moving left or right...meaning moving horizontally.......the number is added inside the parenthesis.

This one is moving up or down ....meaning moving horizontally........so the number is added outside the parenthesis. If it moves up then add(+)..........if it moves down then subtract(-). The formula used for horizontal shifts is, y=lXl + k
.Here k will become negative or remain positive based on the given data.

Now,
It's a horizontal shift, so we can eliminate C and D.
It moves down so we will subtract and therefore we can eliminate A

so the answer is B.
lets check our answer by using the formula

Y = lxl + k
moves 2 units down so our k = (-2)
Y = lxl + (-2) [substitute k]
Y = lxl - 2

6 0

2 years ago

Read 2 more answers

I need help solving this problem: 5x+8+3x=8+7x-6

Alex787 [66]

Hope this will help u....

5 0

3 years ago

2. The robot was initially placed at position (6,9), and at = 2 seconds, its position is (10,15).

qaws [65]

$\bf ~~~~~~~~~~~~\textit{distance between 2 points}
\\\\
\begin{array}{ccccccccc}
&&x_1&&y_1&&x_2&&y_2\\
% (a,b)
&&(~ 6 &,& 9~) 
% (c,d)
&&(~ 10 &,& 15~)
\end{array}~~~ 
% distance value
d = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2}
\\\\\\
d=\sqrt{(10-6)^2+(15-9)^2}\implies d=\sqrt{4^2+6^2}\implies d=\sqrt{52}
\\\\\\
d\approx 7.2$

what's its speed? well, it traveled √(52) in 2 seconds, so is simply √(52)/2, which is about 3.6 units per second.

4 0

3 years ago

Find the sum: 2 + 9 + 16 + ... + 37

iris [78.8K]

Step-by-step explanation:

Sum of arithmetic terms = n/2 × [2a + (n - 1)×d], where 'a' is the first term, 'd' is the common difference between two numbers, and 'n' is the number of terms.

this is the same as n/2 × (a1 + an), because

an = a1 + (n-1)×d

so, for the series above :

a or a1 = 2

d = 7, as every new term is the previous term plus 7.

for n

37 = a1 + (n-1)×d = 2 + (n-1)×7

and now solve for n

35 = 7n - 7

42 = 7n

n = 6

so, the sum of all terms is

6/2 × (2+37) = 3×39 = 117

7 0

2 years ago