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3 years ago

1) Find the value of two numbers if their sum is 12 and their difference is 4.

Mathematics

1 answer:

Ivahew [28]3 years ago

4 0

Numbers are 4 and 8

Step-by-step explanation:

Step 1:

Let the numbers be x and y. Given that their sum is 12 and difference is 4. Form equations for this data.

⇒ x + y = 12 ------ (1)

⇒ x - y = 4 -------- (2)

Subtract eq (2) from (1)

⇒ 2x = 8

⇒ x = 4

Step 2:

Find y.

⇒ y = 12 - x = 12 - 4 = 8

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How do you solve the system by substitution? y = 4x + 24 y = 5x

makkiz [27]

Set up a new equation of 5x=4x+24 and solve it should be x=24

3 0

3 years ago

Read 2 more answers

What is the solution to this system of equations? 4x + 5y = 7

Nutka1998 [239]

Answer:

(-2, 3)

Step-by-step explanation:

4x + 5y = 7

3x - 2y = -12

Let's solve this by elimination. We want to eliminate one variable at a time. This means we need to multiply the equations to create a common multiple to cancel out a variable.

Let's work with y.

5y and -2y: For these values to cancel out, we need to multiply each term to create a common multiple.

2(4x + 5y = 7)

5(3x - 2y = -12)

Multiply.

8x + 10y = 14

15x - 10y = -60

Eliminate.

23x = -46

Divide both sides by 23.

x = -2

Now that we know x, let's plug it back into one of equations to find y.

4x + 5y = 7

4(-2) + 5y = 7

Multiply.

-8 + 5y = 7

Add.

5y = 15

Divide.

y = 3

Now we know x and y; let's plug both back into the equation we have not checked yet.

3x - 2y = -12

3(-2) - 2(3) = -12

Multiply.

-6 - 6 = -12

Subtract.

-12 = -12

Your solution is correct.

(-2, 3)

Hope this helps!

8 0

3 years ago

Find f if f′(x)=2x−3/x^4, x>0 and f(1)=2.

slavikrds [6]

$f'(x)=2x-\dfrac3{x^4}$
$\displaystyle\int f'(x)\,\mathrm dx=\int\left(2x-\frac3{x^4}\right)\,\mathrm dx$
$f(x)=x^2+\dfrac1{x^3}+C$

Given that $f(1)=2$ , we get

$2=1^2+\dfrac1{1^3}+C$
$2=2+C$
$\implies C=2$

so that

$f(x)=x^2+\dfrac1{x^3}$