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3 years ago

In the solution of the equation 5 - 3x = 2x + 9, 3x is added to the equation first. Which of the following should be done next?

2 answers:

4 0

<span>In finding the solution for x, the idea is to isolate the variable on one side of the equation
5 - 3x = 2x + 9 |3x is added to the equation first
5 = 5x + 9 | 9 is subtracted from EQ second
-4 = 5x </span>

BartSMP [9]3 years ago

3 0

Subtract 5 from the left side and add it to the right side

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Write 0.6 as a fraction ?

satela [25.4K]

Answer:

6/10 ; 3/5 (simplified form)

Step-by-step explanation:

To solve, note the decimal place value. Move the decimal point to the right two place values, and set it over 100

0.6 = 60/100

Simplify the fraction. Divide common factors from the numerator & denominator (20 in this case)

(60/100)/(20/20) = 3/5

3/5 is your answer

7 0

3 years ago

Read 2 more answers

Compare the light gathering power of an 8" primary mirror with a 6" primary mirror. The 8" mirror has how much light gathering p

tankabanditka [31]

Answer:

1.778 times more or 16/9 times more

Step-by-step explanation:

Given:

- Mirror 1: D_1 = 8''

- Mirror 2: D_2 = 6"

Find:

Compare the light gathering power of an 8" primary mirror with a 6" primary mirror. The 8" mirror has how much light gathering power?

Solution:

- The light gathering power of a mirror (LGP) is proportional to the Area of the objects:

LGP ∝ A

- Whereas, Area is proportional to the squared of the diameter i.e an area of a circle:

A ∝ D^2

- Hence, LGP ∝ D^2

- Now compare the two diameters given:

LGP_1 ∝ (D_1)^2

LGP ∝ (D_2)^2

- Take a ratio of both:

LGP_1/LGP_2 ∝ (D_1)^2 / (D_2)^2

- Plug in the values:

LGP_1/LGP_2 ∝ (8)^2 / (6)^2

- Compute: LGP_1/LGP_2 ∝ 16/9 ≅ 1.778 times more

6 0

3 years ago

Use a system of equations to solve this problem. Dr. Graham currently has two acid solutions. She only has a 60% acid solution a

Natalka [10]

<span>Dr. Graham currently has two acid solutions.
60% acid AND 20% acid </span>
Dr. Graham needs 30 L of a 50% acid solution
We set up 2 equations in which s = 60% acid and t = 20% acid
A) s + t = 30
B) .60s + .20t = (.50 * 30)
We multiply equation A by -.20
A) = -.20s -.20t = -6 then we add it to B)
B) .60s + .20t = 15
.40s = 9
s = 22.5
t = 7.5
So, she needs to mix 22.5 liters of 60% acid with 7.5 liters of 20% acid.

Source:
http://1728.org/mixture.htm

4 0

3 years ago

What is a, the initial amount, for the function: f(x) = 300(1.16)*?

jeka94

<h3>Answer: 300</h3>

====================================================

Explanation:

One general template of exponential functions is

f(x) = a*(b)^x

The 'a' is the initial amount, which in this case is a = 300

----------------------

Extra info:

The b is the base of the exponential, which is b = 1.16

The value of b is helpful to determine if you have exponential growth or decay, and how much of either. Because b = 1.16 is greater than 1, it indicates exponential growth. The rate of growth is found by solving 1+r = 1.16 to get r = 0.16, which leads to 16% growth.

6 0

3 years ago

dimulka [17.4K]

Answer:

15) Ellen is 12 years old.

16) Don't know what value you are looking for but x=(17/4) while y=(7/4) since the set of equations is 2x-2y=5 and x+y=6.

Step-by-step explanation:

15) Ellen (E) is currently twice as old as Maria (M).

Twice means to multiply by 2.

E=2M is therefore the equation for this part of the problem.

In 6 years, Maria (M) will be 2/3 as old as Ellen (E). Keep in my Maria as aged 6 years (M+6) and Ellen as aged 6 years (E+6):

M+6=(2/3)(E+6).

So we have this system to solve:

E=2M

M+6=(2/3)(E+6).

I'm going to replace the E in the second equation with 2M since the first equation says E=2M:

M+6=(2/3)(E+6) with E=2M:

M+6=(2/3)(2M+6)

Distribute:

M+6=(4/3)M+(12/3)

Reducing 12/3 to 4:

M+6=(4/3)M+4

Subtract 4 on both sides:

M+2=(4/3)M

Subtract M on both sides:

2=(4/3)M-M

Find a common denominator:

2=(4/3)M-(3/3)M

Combine like terms:

2=(1/3)M

Multiply both sides by the reciprocal of 1/3 which is 3:

3(2)=3(1/3)M

6=1M

6=M

M=6

Maria is six years old.

Recall E=2M.

So if M=6, then E=2(6)=12.

So currently E is twice as old as M since 6(2)=12.

In six years, M will be 12 which E will be 18.

M (12) is two-thirds as old as E (18) since 12=2/3(18)

16)

2x-2y=5

x + y=6

Your question doesn't state which value it is looking for.

Anyways I'm going to solve the system for the point (x,y) and then you can decide which part of this answer to use.

I'm going to solve this system by elimination. Each equation already has the same form: ax+by=c. I just need a column with the variables to be opposite or the same.

I'm going to multiply both sides of equation 2 by 2:

2x-2y=5

2x+2y=12

Now I have opposites in a column: -2y and 2y.

When you add opposites you get 0 so this is what you want to use elimination.

We are going to add the equations now:

2x-2y=5

2x+2y=12

------------------Adding!

4x+0y=17

4x =17

Divide both sides by 4:

x =17/4

Now if x=17/4 and x+y=6, then we have that (17/4)+y=6.

Subtracting 17/4 on both sides gives us y=6-(17/4).

Finding a common denominaotr gives us y=(24/4)-(17/4).

Simplifying this gives us y=(7/4).

The point of intersection (the solution) is (17/4 , 7/4)

7 0

3 years ago