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2 years ago

Solve the system using addion 7x+2y=-13 -7x+y=25

Mathematics

1 answer:

larisa [96]2 years ago

5 0

Answer:

x = -3

y = 4

Step-by-step explanation:

7x + 2y = -13

-7x + y = 25

3y = 12

-7x + y = 25

y = 4

-7x + 4 = 25

y = 4

-7x = 21

y = 4

x = -3

there is only 1 solution for this equation is (-3,4)

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Is 26 a perfect square explain

Nataly_w [17]

No because there is not a number that is the same number that equals to 26

5 0

3 years ago

What are the fourth roots of 6+6√(3i) ?

Helen [10]

Answer:

Step-by-step explanation:

The genral form of a complex number in rectangular plane is expressed as z = x+iy

In polar coordinate, z =rcos ∅+irsin∅ where;

r is the modulus = √x²+y²

∅ is teh argument = arctan y/x

Given thr complex number z = 6+6√(3)i

r = √6²+(6√3)²

r = √36+108

r = √144

r = 12

∅ = arctan 6√3/6

∅ = arctan √3

∅ = 60°

In polar form, z = 12(cos60°+isin60°)

z = 12(cosπ/3+isinπ/3)

To get the fourth root of the equation, we will use the de moivres theorem; zⁿ = rⁿ(cosn∅+isinn∅)

z^1/4 = 12^1/4(cosπ/12+isinπ/12)

When n = 1;

z1 = 12^1/4(cosπ/3+isinn/3)

z1 = 12^1/4cis(π/3)

when n = 2;

z2 = 12^1/4(cos2π/3+isin2π/3)

z2 = 12^1/4cis(2π/3)

when n = 3;

z2 = 12^1/4(cosπ+isinπ)

z2 = 12^1/4cis(π)

when n = 4;

z2 = 12^1/4(cos4π/3+isin4π/3)

z2 = 12^1/4cis(4π/3)

8 0

3 years ago

–20 ÷ 5 = I need help

Rashid [163]

The answer is -4
-20 divided by 5 ^

7 0

2 years ago

Three hikers are dividing the costs of a hiking trip evenly. They bought two permits that cost $15 each, three tram tickets that

cestrela7 [59]

Each hiker owes $41 or 4100 cents for the hiking trip.

Explanation

Cost of each permit is $15. So, the cost of two permits will be: $(\$15*2)= \$30$

Cost of each tram ticket is $19. So, the cost of three tickets will be: $(\$19*3)=\$ 57$

Cost of one can of bear spray is $36.

So, the total cost of the hiking trip $=\$30+\$57+\$36=\$123$

As the three hikers are dividing the total costs of the trip evenly, so each hiker owes $=\frac{\$123}{3}=\$41$ or 4100 cents.

3 0

2 years ago

Calculate the gradient of the line using rise/run method.

Lapatulllka [165]

Given:

The graph of line.

To find:

The gradient of the line using rise/run method.

Solution:

We know that the gradient of a line is also known as slope.

$Slope=\dfrac{Rise}{Run}$

Consider the two intercepts, then rise is distance between origin and y-intercept and run is the distance between origin and the x-intercept. But rise must be negative because the value of y decreased from 3 to 0.

$Rise=-3$

$Run=2$

Now,

$Slope=\dfrac{Rise}{Run}$

$Slope=\dfrac{-3}{2}$

The gradient of the line is $-\dfrac{3}{2}$ .

Therefore, the correct option is C.

8 0

3 years ago