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3 years ago

Please help me solve 3x + 4y =15 and 3x - y = 30 it is for Algebra I

Mathematics

2 answers:

Makovka662 [10]3 years ago

7 0

Answer:

Step-by-step explanation:

Given the simultaneous equation

3x+4y=15. Equation 1

3x-y=30. Equation 2

Using elimination method

Sutract equation 2 from 1

Then, will have

3x-3x+4y--y=15-50. -×-=+

4y+y=-15

5y=-15

Divide Both sides by 5

y=-15/5

y=-3

From equation 2

3x-y=30

3x--3=30

3x+3=30

3x=30-3

3x=27

Divide both side by 3

x=27/3

x=9

Then, x=9 and y=-3

Colt1911 [192]3 years ago

7 0

Answer:

x=7 y=-9

Step-by-step explanation:

Use a system of equations to solve.

3x-y=30 changes to y=-30+3x

This can then be substituted into the other equation.

3x+4(-30+3x)=15

solve for x

X=7

Now use 7 in the other equation.

y=-30+x(7)

y=-9

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Step-by-step explanation:

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3 years ago

What is the least positive integer divisible by the numbers 2, 4, and 7?

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Answer:

Least positive integer divisible by the numbers 2, 4, and 7 is 28

Step-by-step explanation:

We can find the least positive integer divisible by the numbers 2, 4, and 7 by taking the LCM

First lets List all prime factors for each number.

Prime Factorization of 2

2 is prime => $2^1$

Prime Factorization of 4 is:

2 x 2 => $2^2$

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For each prime factor, find where it occurs most often as a factor and write it that many times in a new list.

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3 years ago