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3 years ago

How do I solve this system using substitution: y = x + 4; y = 3x

Mathematics

2 answers:

Kisachek [45]3 years ago

8 0

Y = x + 4
y = 3x

3x = x + 4
- x - x 
2x = 4
2 2
x = 2
y = x + 4
y = 2 + 4
y = 6
(x, y) = (2, 6)

Olin [163]3 years ago

4 0

You just do
3x=x+4
subtract x from both sides
2x=4
divide 2 from both sides
x=2
y=2+4
y=6
(x,y)= (2,6)

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Louiza changes £320 into Euros. £1 is Worth 1.14 euros. How many euros does she receive?

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Answer:

she received 364.80 euros

Step-by-step explanation:

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3 years ago

The sum of two numbers is 30. The difference of twice the larger number and three times the smaller number is 5. What is the pos

natali 33 [55]

Let’s give these two numbers variables
Let ‘a’ be the larger number
Let ‘b’ be the smaller number

Now from the question we know:
a + b = 30 or a = 30 - b
2a - 3b = 5

Now, let’s plug the first equation into the second to find ‘b’:

2(30 - b) - 3b = 5
60 - 2b - 3b = 5
60 - 5b = 5
55 = 5b
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Now we solve for ‘a’:
a = 30 - b
a = 30 - 11
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Now the question asks for the positive difference between the two numbers, so:
a - b = ?
19 - 11 = 8

Hope this helps!

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3 years ago

A truangular bandana has an area of 42 square inches. The height of the triangle is 5 1/4 inches. Enter and solve an equation ti

nasty-shy [4]

Answer: The length of the base of the triangle is 16 inches.

Step-by-step explanation:

Hi, to answer this question we have to apply the next formula

Area of a triangle (A) = base x height x 1/2

Replacing with the values given:

42 = b (5 1/4) 1/2

Solving for b (lenght of the base)

42 / (5 1/4) 1/2 = b

16 in = b

The length of the base of the triangle is 16 inches.

Feel free to ask for more if needed or if you did not understand something.

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3 years ago

What quantity should be added to both sides of this equation to complete the square x^2+12x=-15

anzhelika [568]

Answer:

Step-by-step explanation:

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3 years ago

Use two unit multipliers to convert 628 kilometers to centimeters

irina [24]

Using two unit multiplier 628 km is equal to 62800000 cm

Solution:

628 kilometer to centimeter

We will go from kilometers to meters to centimeters.

Start by putting 628 km over 1:

$\frac{628 km}{1}$

We want to get rid of km and bring in m.

We know that 1000 m = 1 km.

Since km is in the numerator, we will make the first unit multiplier by putting 1 km in the denominator and 1000 m in the numerator, so the km will cancel. So we multiply by the unit multiplier,

$\frac{628 km}{1} \times \frac{1000m}{1km}$

Now the km's will cancel:

$\frac{628}{1} \times \frac{1000m}{1}$

Now we want to get rid of m and bring in cm.

We know that 100 cm = 1 m.

Since meter is in the numerator, we will make the first unit multiplier by putting 1 meter in the denominator and 100 cm in the numerator, so the meter's will cancel. So we multiply by the unit multiplier

$\frac{100cm}{1m}$

$\frac{628}{1} \times \frac{1000m}{1} \times \frac{100cm}{1m}$

We cancel the m's and we end up with:

$628 \times 1000 \times 100 cm$

= 62800000 cm

Thus 628 km is equal to 62800000 cm

5 0

3 years ago