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1 year ago

Solve the systems of equations by substitution. 2x+y=-2 3x-y=7

Mathematics

1 answer:

lukranit [14]1 year ago

5 0

Answer:

To solve the system of equations by substitution:

2x+y=-2

3x-y=7

first solve for y:

2x+y=-2

y=-2x-2

Then plug ^^ equation for y in the other equation

3x-(-2x-2)=7

5x+2=7

5x=5

x=1

Then solve for y:

2(1)+y=-2

y=-4

Final answer is x = 1 and y = -4

Hope it helps!

top answer row

315 E7 so a 5 in that box.

8 0

2 years ago

a wildlife photographer photographs a crocodile and then paddles against a river current for 6 km. Then, hoping to photograph a

rusak2 [61]

Answer:

5 km/h or 6 km/h

Step-by-step explanation:

Let the speed of the boat be x
Speed against the current in the river is x - 2

Time in the river:

6/(x - 2)

Time in the lake:

15/x

The difference:

6/(x - 2) = 15/x - 1

Solve for x to find the speed of the boat

Multiply both sides by x(x - 2) to clear the fraction:

6x = 15(x - 2) - x(x - 2)
6x = 15x - 30 - x² + 2x
x² - 11x + 30 = 0
(x - 5)(x - 6) =0
x -5 = 0, x - 6 = 0
x = 5 km/h, x = 6 km/h

4 0

3 years ago

Read 2 more answers

Decide whether the equations is a trigonometric function identity, EXPLAIN.

hodyreva [135]

(1) Answer: Identity true

$\cos^2x(1+\tan^2x)=\cos^2x(1+\frac{sin^2x}{cos^2x})=\\= \cos^2x\frac{cos^2x+sin^2x}{cos^2x}=1$

(2) Answer: Identity true

$\sec x \tan x(1-\sin^2x)=\sin x\\\frac{1}{\cos x}\frac{\sin x}{\cos x}(\cos^2x)=\sin x\\\sin x = \sin x$

(3) Answer: Identity true

$\sin^2(\theta)\csc^2(\theta)=\sin^2(\theta)+\cos^2(\theta)\\\sin^2(\theta)\frac{1}{\sin^2(\theta)}=\sin^2(\theta)+\cos^2(\theta)\\1 = 1$

7 0

2 years ago

I’m confused #7 pls help

ki77a [65]

9x+11-4x+3=24

always combine like terms first. Combine all the x's and all numbers.

5x+14=24

Therefore, the answer is D.

6 0

3 years ago

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Give CROWN JUST NEED ANSWER True or false: milliliter is a unit we use to measure the length

ruslelena [56]

Answer: False

Step-by-step explanation:

Milliliter is used to measure liquids.

Hope this helps :)

6 0

2 years ago

Read 2 more answers