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3 years ago

Translate this word problem as a system of equations and then solve using substitution.

Mathematics

1 answer:

Assoli18 [71]3 years ago

4 0

Answer:

The numbers are 21 and 63

Step-by-step explanation:

let one number be x

let the other number be 3 times the other = 3x

3x + x = 84

4x = 84

x = 21

3x = 3×21 = 63

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After being rearranged and simplified, which of the following equations could be solved using the quadratic formula? Check all t

Naddika [18.5K]

Answer:

The options 2x² + x² + x = 30 and 9x + 3x² = 14 + x + 1, and -x² + 4x + 7 = - x² - 9

Step-by-step explanation:

After being rearranged and simplified, which of the following equations could be solved using the quadratic formula?

The answers are:

2x² + x² + x = 30

9x + 3x² = 14 + x + 1

-x² + 4x + 7 = - x² - 9

3 0

3 years ago

Read 2 more answers

Solve 3(x - 4) = 11x

Ivanshal [37]

Answer:

$x = \frac{-3}{2}$

Step-by-step explanation:

3(x - 4) = 11x

Expand the brackets:

3x - 12 = 11x

Subtract 3x from both sides to isolate the -12:

3x - 12 = 11x

3x - 3x - 12 = 11x - 3x

-12 = 8x

8x = -12

Divide both sides by 8:

$\\\frac{8x}{8} = \frac{-12}{8}\\x = \frac{-12}{8}\\$

Simplify fraction:

$x = \frac{-12}{8}$

$x = \frac{-12 \div 4}{8 \div 4}\\x = \frac{-3}{2}$

Hope this helps!

7 0

3 years ago

Trevor and $826 on account during 2.5% annual interest for seven years.

photoshop1234 [79]

Trevor invested $ 4720

Solution:

Given that, Trevor earned $ 826 on account during 2.5% annual interest for seven years

We can simple interest formula

The formula for simple interest is given as:

$\text{ Simple Interest } = \frac{p \times n \times r}{100}$

Where,

"p" is the principal

"n" is the number of years

"r" is the rate of interest

Here given that,

Principal = p = ?

rate of interest = r = 2.5 %

number of years = n = 7

Simple interest earned = 826

Substituting the values in above formula,

$826 = \frac{p \times 7 \times 2.5}{100}\\\\82600 = p \times 7 \times 2.5\\\\82600 = 17.5p\\\\p = \frac{82600}{17.5}\\\\p = 4720$

Thus he invested $ 4720

7 0

3 years ago

28/21 = 42/x solve for x

Scilla [17]

28/21=42/x multiply both sides by x

28/21x=42 divide by 28/21 on both sides ( or multiply both sides by 21/28)

X= 63/2
X= 31 1/2

8 0

3 years ago

Read 2 more answers

Decide whether it would be more convenient to solve the system of equations by substitution or elimination.

nikklg [1K]

It is more convinient to use substitution

5 0

3 years ago