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3 years ago

Solve the system of equations by substitution:

Mathematics

1 answer:

Sedaia [141]3 years ago

3 0

Answer:

x+(x-2)=12

2x-2=12

2x=12+2

2x=14

x=14/2

x=7

x+y=12

7+y=12

y=12-7

y=5

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Solve for x on the interval [0, 2pi] Sinx = cosx + 1

lisov135 [29]

Answer:

Step-by-step explanation:

Solve for x on the interval [0, 2pi]

Given the equation

Sinx = cosx + 1

Square both sides of the equation

Sin²x = (cos x + 1)²

Sin²x = cos²x + 2cos x + 1

Since Sin²x = 1 - cos²x

1 - cos²x = cos²x + 2cos x + 1

Collect like terms

1-1-cos²x-cos²x-2cos x = 0

-2cos²x-2cos x = 0

-2cos²x = 2cos x

-cosx = 1

cos x = -1

x = arccos -1

x = 180 degrees

Hence the value of x = π

8 0

3 years ago

Simplify 2(x + y) + 3(x + y).

Sophie [7]

Answer:

5x+5y

Step-by-step explanation:

3 0

3 years ago

If F= - 1 - 9 , G= 7 - 9 , and d=3, what is dF+G?

olga2289 [7]

Hello! -1 - 9 is -10. F = -10. 7 - 9 is -2. G = -2.

F = -10
G = -2
d = 3

Okay, so because d and F are beside each other, we multiply both of the values. Let's plug in the values. -10 * 3 is -30. This is because one negative and one postive make a negative number. Now, we add the number. Because it is negative, we have to go into the negatives more. -30 + (-2) is -32. There. The answer is -32.

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3 years ago

Ratio of red marbles to blue marbles is 2:3. If there are 6 red marbles, how many blue marbles are there

miskamm [114]

Answer:

6:9

Step-by-step explanation:

Lets assume the relationship between the amount of blue and red marbles are proportional. If there are 6 red marbles , then we would need need to find out how much times you multiplied 2 by to get.

6/2 is 3, which means that you multiplied the red marbles by 3 to get 6 of them.

Since the relationship between red and blue marbles is equivalent, we just need to multiply the blue marbles by 3 as well, to even it out.

3x3=9

There are 9 blue marbles if there are 6 red marbles.

5 0

3 years ago

7th grade math help me pleaseee

Marianna [84]

no, -6+2= -4

not -6 +(-2)

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3 years ago