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3 years ago

Elena solved the equation 2(x – 9) = 10 In the following way. What mistake did she make?

Mathematics

2 answers:

dmitriy555 [2]3 years ago

7 0

She subtracted instead of adding.
2x-18=10
You add 18 to both sides
So it would be 2x=28
Then you divide 2 on both sides so x=14

bezimeni [28]3 years ago

4 0

Answer: Subtract 18 on both sides is wrong. Its supposed to be add 18 on both sides.

Step-by-step explanation:

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2. Find the value of x for which l | | m.

joja [24]

2x-5=95 due to the alternate interior angles thm so you just add 5 to 95 to get 2x=100 then divide by 2 to get x=50!

7 0

4 years ago

A linear model is given for the data in the table: y=1.25x+2.

Fed [463]

Answer:

Option A

Step-by-step explanation:

Given that A linear model is given for the data in the table: y=1.25x+2.

Let us write observed values for each x and also the predicted values as per equation.

x 2 3 4 8 10 16 20 24 Total

y((O) 3 4 7 12 16 22 28 30

y(P) 4.5 5.75 7 12 14.5 22 27 32

DEv 1.5 1.75 0 0 1.5 0 1 2 7 75

where y(0) represents observed y or y in the table given

y(P) gives values of y predicted as per the equation 1.25x+2

Dev represents the absolute difference

Hence answer is option

A.7.75

8 0

3 years ago

Solve the system of equations. y=7x y=2x + 20 x=? y=?

alekssr [168]

X=4, y=28. 7x=2x+20, so subtract 2x from both sides and you’ll get 5x=20. Divide both sides by 5 and you’ll get x=4. Substitute this into the other equations and they will both equal 28.

6 0

3 years ago

How would I solve this?

lutik1710 [3]

Answer:

It is rotated by 72 degrees.

Step-by-step explanation:

Since it is a regular polygon,

when u connect all the corners of it to the middle of the polygon, they will meet at a point i.e, CENTER.

The sum of the angles subtended by all the sided at the center will be 360 degrees.

As there are 60 sides, the angle subtended by each side at the center will be 6 degrees.

Because,

$\frac{360}{60} = 6$

As the polygon rotates every minute and it is rotated for 12 minutes,

$12*6 = 72$

( For every minute, it will be rotated by 6 degrees.

so, for 12 minutes it should be rotated by 12 times 6 ( 12*6) = 72 degrees)

So, after 12 minutes it will be rotated by 72 degrees.

5 0

3 years ago

Number 1 and 2 please (25 points)

Elenna [48]

Answers:

1) $(3x+2)+(4-5x)=-2x+6$

$(3+2i)+(4-5i)=7-3i$

2) $(1-3x)(2+x)=-3x^{2}-5x+2$

$(1-3i)+(2+i)=5-5i$

Step-by-step explanation:

In mathematics there are rules related to complex numbers, specifically in the case of addition and multiplication:

Addition:

If we have two complex numbers written in their binomial form, the sum of both will be a complex number whose real part is the sum of the real parts and whose imaginary part is the sum of the imaginary parts (similarly as the sum of two binomials).

For example, the addition of these two binomials is:

$(3x+2)+(4-5x)=3x-5x+2+4=-2x+6$

Similarly, the addition of two complex numbers is:

$(3+2i)+(4-5i)=3+4+2i-5i=7-3i$ Here the complex part is the number with the $i$

Multiplication:

If we have two complex numbers written in their binomial form, the multiplication of both will be the same as the multiplication (product) of two binomials, taking into account that $i^{2}=-1$ .

For example, the multiplication of these two binomials is:

$(1-3x)(2+x)=2+x-6x-3x^{2}=-3x^{2}-5x+2$

Similarly, the multiplication of two complex numbers is:

$(1-3i)+(2+i)=2+i-6i-3i^{2}=2-5i-3(-1)=5-5i$

8 0

4 years ago