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3 years ago

3x-4 when x = 7 how do I do this equation I’m confused

Mathematics

2 answers:

natka813 [3]3 years ago

6 0

Plug the 7 in where it says x.
3x-4
3(7)-4
21-4
17

Andreas93 [3]3 years ago

5 0

Answer:

17.

Step-by-step explanation:

1. Plug in 7 for x.

2. 3(7)-4

3. 3 times 7 is 21.

4. 21 minus 4 is 17.

5. The Answer is 17.

You might be interested in

Lindsey Wilson was the top scorer in a women's professional basketball league for the 2006 regular season, with a total of 814 p

baherus [9]

Answer:

The number of free throws, two-point throw, and three-point throw are 135, 173, and 111 respectively.

Step-by-step explanation:

Let x,y, and z are the numbers of two-point field goals, numbers of three-point field goals, and the number of free-throws (one-point goal) respectively.

The total points= 814

$\Rightarrow 2x+3y+z=814\;\cdots(i)$

As the number of two-point goals was 49 less than double the number of three-point field goals she made.

$\Rightarrow x=2y-49 \;\cdots(ii)$

Again, the number of free goals was 38 less than the number of two-point field goals she made.

$\Rightarrow z=x-38\;\cdots(iii)$

From equations (i) and (iii)

2x+3y+x-38=814

$\Rightarrow 3x+3y=852$

$\Rightarrow x+y=284$

$\Rightarrow 2y-49+y=284$ [using equation (ii)]

$\Rightarrow 3y=333$

$\Rightarrow y=111$

From equation (ii),

$x= 2\times111-38=173$

From equation (iii),

$z=173-38=135$ .

Hence,

The number of free throws, z= 135

The number of two-point throw, x=173

The number of three-point throw, y=111.

3 0

3 years ago

600g of 20% of the normal price of £5

max2010maxim [7]

Answer:

Step-by-step explanation:

600g of 20%

100 - 20 = 80

600 = 80%

/80%

7.5 = 1%

x100

750 = 100%

£750

Sorry I don’t know what else to write. Hopefully, this guarantees you a mark.

7 0

3 years ago

Ben, Tim, and Sam have to do a certain job. Ben can finish the job in 5 hours. Tim can finish the job in 6 hours. Sam can finish

Brut [27]

x is 7.5 hours

Step-by-step explanation:

Ben, Tim, and Sam have to do a certain job

Ben can finish the job in 5 hours
Tim can finish the job in 6 hours
Sam can finish the job in x hours
The three of them can finish the job in 2 hours if they work together

We need to find x

∵ Ben can finish the job in 5 hours

∴ The rate of Ben = $\frac{1}{5}$

∵ Tim can finish the job in 6 hours

∴ The rate of Tim = $\frac{1}{6}$

∵ Sam can finish the job in x hours

∴ The rate of Sam = $\frac{1}{x}$

They will working together to finish the job in two hours, that means the sum of their rate is equal to 1/2

∵ They can finish the job in 2 hours if they work together

∴ $\frac{1}{5}+\frac{1}{6}+\frac{1}{x}=\frac{1}{2}$

To add the fractions find the LCM for all denominators to make all fractions with same denominators

∵ The LCM of 5, 6 ans x is (5 × 6 × x) = 30 x,

- Divide it by each denominator to find the new numerators

∵ 30 x ÷ 5 = 6 x , 30 x ÷ 6 = 5 x , 30 x ÷ x = 30

- Change all the denominators to 30 x and then write the new

numerators of each fraction

∴ $\frac{6x}{30x}+\frac{5x}{30x}+\frac{30}{30x}=\frac{1}{2}$

Add the numerators and put the sum over 30 x

∵ $\frac{11x+30}{30x}=\frac{1}{2}$

- By using cross multiplication

∴ 2(11 x + 30) = 1(30 x)

- Simplify the both sides

∴ 22 x + 60 = 30 x

- Subtract 22 x from both sides

∴ 60 = 8 x

- Divide both sides by 8

∴ 7.5 = x

∴ The value of x is 7.5 hours

x is 7.5 hours

Learn more:

You can learn more about the word problems in brainly.com/question/10712420

#LearnwithBrainly

5 0

3 years ago

The Fall Festival charges $0.75 per ticket for the rides. Kendall bought 18 tickets for rides and spent a total of $33.50 at the

PIT_PIT [208]

Part (a)

The variable y is the dependent variable and the variable x is the independent variable.

Part (b)

The cost of one ticket is $0.75. Therefore, the cost of 18 tickets will be:

$0.75\times 18=13.5$ dollars

Now, we know that Kendall spent her money only on ride tickets and fair admission and that she spent a total of $33.50.

Therefore, the price of the fair admission is: $33.50-$13.50=$20

If we use y to represent the total cost and x to represent the number of ride tickets, the linear equation that can be used to determine the cost for anyone who only pays for ride tickets and fair admission can be written as:

$y=0.75x+20$ ......Equation 1

Part (c)

The above equation is logical because, in general, the total cost of the rides will depend upon the number of ride tickets bought and that will be 0.75x. Now, even if one does not take any rides, that is when x=0, they still will have to pay for the fair admission, and thus their total cost, y=$20.

Likewise, any "additional" cost will depend upon the number of ride tickets bought as already suggested. Thus, the total cost will be the sum of the total ride ticket cost and the fixed fair admission cost. Thus, the above Equation 1 is the correct representative linear equation of the question given.

4 0

3 years ago

Which relation is displayed in the table? {(3,3), (3, 7), (5, 8), (9,0)} {(3,3), (7, 3), (8, 5), (0,9)} {(3,3), (3, 7), (5, 9)

bulgar [2K]

Answer:

{(3,3), (3, 7), (5, 8), (9,0)

Step-by-step explanation:

The first number of an ordered pair is the x value and the second number is the y value.

3 0

2 years ago