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3 years ago

Solve the system of linear equations x + y = 4 and 2x + 3y = 0

1 answer:

8 0

solve this answer by using substitution. set the first equation to x=-y+4 then substitute -y+4 for x in the second equation.

2(-y+4) + 3y=0

-2y+8 + 3y=0

y+8=0

y=-8

now use -8 and solve for x

x+(-8)=4

x=12

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How much does 4 5/7 kg of candy cost if 5/6 kg costs $7.50

Aliun [14]

Answer:

It costs $42.43

Step-by-step explanation:

Lets explain how to solve the problem

- The cost of $\frac{5}{6}$ kilogram of candy is $7.5

- We need to find the cost of $4\frac{5}{7}$ kilogram

We can use the ratio to find the answer

======= Dollar : Kilogram

======= 7.5 : $\frac{5}{6}$

======= c : $4\frac{5}{7}$

By using cross multiplication

∴ c × $\frac{5}{6}$ = 7.5 × $4\frac{5}{7}$

∵ $4\frac{5}{7}$ = $\frac{4*7+5}{7}$

∴ $4\frac{5}{7}$ = $\frac{33}{7}$

∴ c × $\frac{5}{6}$ = 7.5 × $\frac{33}{7}$

∴ c × $\frac{5}{6}$ = $\frac{495}{14}$

Divide both sides by $\frac{5}{6}$

∴ c = $\frac{495}{14}$ ÷ $\frac{5}{6}$

Change the division sign to multiplication sign and reciprocal the

fraction after the division sign

∴ c = $\frac{495}{14}$ × $\frac{6}{5}$

∴ c = $\frac{297}{7}$ = 42.43 dollars

∵ c represents the cost of $4\frac{5}{7}$ kg

∴ It costs $42.43

7 0

3 years ago

Before she started hiking, Jessica’s altimeter read +250 meters. She climbed 200 meters and reached point A, which is at an elev

suter [353]

Point A altimeter reading: +450

Point B altimeter reading: -50

7 0

3 years ago

1.the ratio if the weight of an object on mars to its weight in earth is 9 to 25.If a person weighs 120pouns on earth,how much w

Ilya [14]

Question #1
$\frac{9}{25}=\frac{x}{120}\\\\120(9) = 25x\\\\1080 = 25x\\\\x= 43.2$

For #1, the answer is 43.2

Question #2
$\frac{6}{5} = \frac{2580}{x} \\\\2580(5) = 6x\\\\12900 = 6x\\\\x = 2150$

For #2, the answer is 2150

8 0

2 years ago

38.Randy and Amy left school at the same time and began walking in oppo-

RideAnS [48]

Answer:

DISTANCE=RATE*TIME. THEREFORE

X=3.6*1/6+4.2*1/6 (1/6 HOUR=10 MIN)

X=.6+.7

X=1.3 KM IS HOW FAR THEY WIL BE APART AFTER 10 MINUTES.

Step-by-step explanation:

7 0

2 years ago

Read 2 more answers

100 POINTS FOR BRAINLIEST! according to the image, whats the answer? Answer wisely for the full 100

stepan [7]

Answer:

Step-by-step explanation:

1. To find the area of a semicircle the formula is

$A=\frac{\pi r^2}{2} \\=\frac{\pi 1^2}{2} \\=6.283m^2$

The square

$A=a^2=2^2=4m^2\\6.283+4=10.283m^2$

2. Triangle

$A=\frac{ab}{2} \\=\frac{6*2.5}{2} \\=7.5m^2\\7.5*2=15m^2$

Rectangle

$A=wl=8*13=104m^2$

$104-15=89m^2$

Semicircle

$A=\frac{\pi r^2}{2} \\=\frac{\pi 3^2}{2} \\\\=14.137m^2$

Square

$A=a^2=6^2=36$

$36-14.137=21.863m^2$

3 0

3 years ago

Read 2 more answers