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3 years ago

Solve the system of equations 2x - y = 11 and x + 3y = -5

Mathematics

2 answers:

Anna11 [10]3 years ago

3 0

Answer:

x = 4, y = -3

Step-by-step explanation:

{2x - y = 11

{x + 3y = -5

You can use the substitution method by solving for x in the second equation:

x + 3y = -5

Subtract 3y from both sides:

x = -3y - 5

Now, substitute this value for x into the first equation:

2x - y = 11

2(-3y - 5) - y = 11

Distribute:

-6y - 10 - y = 11

Add 10 to both sides:

-6y - y = 21

Combine like terms:

-7y = 21

Divide both sides by -7:

Next, substitute this value for x into the second equation:

x + 3y = -5

x + 3(-3) = -5

Multiply:

x - 9 = -5

Add 9 to both sides:

olga55 [171]3 years ago

3 0

Answer:

(7, 3)

Step-by-step explanation:

2x - y =11 2x-y =11

-2(x+3y)= (-5)-2 -2x-6y= 10

Then you will cross out the x, and add.

-7y =21 divide 7

y=-21/7 or y=3

Then you plug in the y where the y is and solve

2x-(3) = 11

2x = 14

x=7

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Answer:

Step-by-step explanation:

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3 years ago

Help me please, Find a, b, and c.

Mama L [17]

Answer:

a = $6*\sqrt{3}$

b = 12

c = $6\sqrt{2}$

Step-by-step explanation:

Since the triangles are right triangles with 60 and 45 degree angles, their side lengths follow special triangles.

A 45-45-90 right triangle has side lengths $1-1-\sqrt{2}$ .

A 30-60-90 right triangle has side lengths $1 - \sqrt{3} -2$ .

Starting with the top triangle which has a 60 degree angle, its side length 6 corresponds to a side length of 1 in the special triangle. It is 6 times bigger so its remaining sides will be 6 times bigger too.

Side a corresponds to side length $\sqrt{3}$ . Therefore, $a = 6*\sqrt{3}$ .

Side b corresponds to side length 2, b = 2*6 = 12.

The bottom triangle has a 45 degree angle, its side length b= 12 corresponds to $\sqrt{2}$ . This means $\sqrt{2}$ was multiplied by $12 = \sqrt{2} * \sqrt{72}$ . This means that side c is $\sqrt{72}=6\sqrt{2}$ .