1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Marina86 [1]
3 years ago
12

HELP PLEASE !!!! Rosana used linear combination to solve the system of equations shown. She did so by multiplying the second equ

ation by a certain number to eliminate the y-terms. What number did Rosana multiply the second equation by?
x - y= 15
0.5x + 0.2y = 25
Mathematics
2 answers:
eimsori [14]3 years ago
8 0

Answer:

She must have multiplied it by 5.

That would've given her:

x - y = 15

2.5x + y = 25

Now we can add them and the y-terms will eliminate each other. Because one is -y, and the other is positive y. -y + y = 0

Allisa [31]3 years ago
6 0
She must have multiplied it by 5.

That would've given her:

x - y = 15
2.5x + y = 25

Now we can add them and the y-terms will eliminate each other. Because one is -y, and the other is positive y. -y + y = 0.
You might be interested in
PLS PLSSSS HURRY PLSSSSSS
Mkey [24]

Answer: The correct answer is 5

Step-by-step explanation:

You take the definition of pi and calculate it to a square root of 2

4 0
2 years ago
Read 2 more answers
It takes two hours for two machines to manufacture 10000 parts. If machine #1 can do the job in one hour less than machine #2, h
elena-14-01-66 [18.8K]

Answer:

Time machine one = 3.56

Time machine two = 4.56

Step-by-step explanation:

Let machine 2 do the job in x hours

Let machine 1 do the job in x - 1 hours.

The general formula for this problem is

Time = A*B/(A + B)

Givens

Time = 2 hours

B = x hours alone

A = x - 1 hours alone.

#################

x *( x - 1)

======= = 2

(x + x - 1)

(x^2 - x)/(2x - 1) = 2

x^2 - x = 2(2x - 1)

x^2 - x = 4x - 2

x^2 - 5x + 2 = 0

a = 1

b = - 5

c = 2

This gives 2 roots

x = 4.56

x = 0.43

The second root will not work because when 1 is subtracted from 0.43 the time give will be minus, which won't work.

Time for machine 2 is 4.56

The time for machine 1 is 3.56

Check

(A * B)/(A + B) = 2

A = 4.56

B = 3.56

Time = 4.56*3.56/(4.56 + 3.56)

Time = 16.2336/(8.12)

Time = 1.9992

The rounding error in the check comes from the rounding error in the times.  

4 0
3 years ago
Round these decimals to 2 decimals places.Please I need some help...
Naddik [55]
A) 1.15
B) 2.87
C) 3.59
D) 4.22
E) 5.74
F) 6.95
G) 7.25
H) 8.64
I) 9.68
J) 28.33
8 0
3 years ago
Read 2 more answers
Information reference tables what is the solution set of the equation log4 (x2 + 3x) − log4 (x + 5) = 1?
faust18 [17]
Use this property of logarithms:

\log_b\left(\dfrac{x}{y}\right)=\log_b x-\log_b y

Your equation transforms into:

log_4\left(\dfrac{x^2+3x}{x+5}\right)=1

Now, you have to apply the definition of a logarithm to express the equation in exponential form:

\dfrac{x^2+3x}{x+5} = 4^1

In case you don't remember, this is the definition of a logarithm:

\log_b x = y \iff b^y = x

The log is the exponent (y) you have to raise the base (b) to in order to get the power (x).

Finally, solve the rational equation:

\dfrac{x^2+3x}{x+5} =4 \iff x^2+3x=4(x+5)
\iff x^2-x-20=0
\iff x=\dfrac{1\pm\sqrt{(-1)^2-4\cdot(-20)}}{2}= \left \{ {{5} \atop {-4}} \right.

The correct answer is d.
5 0
3 years ago
ashton is saving money to buy a new bike. he needs $120 but has only saved 60% so far. How much more money does Ashton need to b
Tasya [4]
Ashton has saved: 60% of $120=(60/100)*$120=(60*$120)/100=$72
Ashton need to buy the bike=$120-$72=$48

He needs to buy the bike=$48
5 0
3 years ago
Other questions:
  • 3469131824 what number is next
    14·1 answer
  • Which function has a range of y&lt;3?<br> y=3(2)<br> y=2(3)*<br> y=-(2)* + 3<br> y= (2)X-3
    12·1 answer
  • a croquet ball weighs 460 grams. together a golf ball and a croquet ball weigh the same as 11 golf balls.how much does 1 golf ba
    9·2 answers
  • Who wants to be friends say me if you do? . also whats 450387 + 40273564
    12·1 answer
  • Which number is the square of an integer and could also be the cube of another integer?
    11·2 answers
  • PLEASE HELP!
    6·2 answers
  • if three bakers can  prepare 15 cakes in 60 minutes, how long will it take six bakers working at the same rate to prepare 20 cak
    15·1 answer
  • . In the adjoining fig-6 , name a) any 4 pairs of intersecting lines. b) 3 non – collinear points c) 4 collinear points
    12·1 answer
  • The hardcore version of a book weighs 7 ounces while it’s paperback version weighs 5 ounces. Forty-five copies of the book weigh
    6·1 answer
  • Please help with this geometry question
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!