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3 years ago

Evaluate the expression x-7, if x= 12. 19 6 05. (please help :( )

Mathematics

2 answers:

Arte-miy333 [17]3 years ago

5 0

Answer:

the answer is 5...............

12345 [234]3 years ago

3 0

Answer:

$5$

Step-by-step explanation:

$\sf x-7$

$\sf x=12$

→ $\sf (12)-7$

→ $\sf 5$

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How do you divide decimals?

MakcuM [25]

You use long division to divide decimals

3 0

4 years ago

Solve the system of equations given . -2x+5y=-3

algol13

For this case we have the following system of equations:

$-2x + 5y = -3\\y-15 = 3x$

We multiply the second equation by -5:

$-5y + 75 = -15x$

Now we add the equations:

$-2x-5y + 5y + 75 = -3-15x\\-2x + 75 = -3-15x\\-2x + 15x = -75-3\\13x = -78\\x = \frac {-78} {13}\\x = -6$

We find the value of the variable "y":

$y = 3x + 15\\y = 3 (-6) +15\\y = -18 + 15\\y = -3$

THE solution is: (-6, -3)

Answer:

(-6, -3)

3 0

4 years ago

Some of the students three scores is 231. If the first is 20 points more than the second, and the sum of the first two is 6 more

Aleks [24]

Answer:

The first score is 109

Step-by-step explanation:

I am assuming that in the first sentence of the question, you meant:

Sum of the students three scores is 231...

First, let the scores of the first second and third student be a, b and c respectively. We are told that:

a + b + c = 231 . . . . . . . .(1) (sum of students three scores is 231)

a = b + 20 . . . . . . . . . . . (2) (the first is 20 points more than the second)

a + b = 6c . . . . . . . . . . . .(3) (sum of the first two is 6 more times the third)

required, find a.

substituting the value of (a + b) in equation (3) into equation (1), we will have the following:

since a + b = 6c . . . (3)

a + b + c = 231 . . . . . (1), becomes,

(a + b) + c = 231

(6c) + c = 231

7c = 231 (divide both sides by 7)

c = 231 ÷ 7 = 33

∴ c = 33

Next, from equation (2), we know that a = b + 20; this can also be written as:

a - 20 = b

∴ b = a - 20 . . . . . . . (4)

Finally, putting the value of b in equation (4) and the value of c calculated above into equation 1, ( a + b + c = 231), we have the following:

a + (a - 20) + 33 = 231

(a + a) - 20 + 33 = 231

2a + 13 = 231

2a = 231 - 13 = 218

a = 218 ÷ 2 = 109

∴ a = 109

we can also calculate for 'b' by substituting for the value of 'a' in equation 4

b = a - 20 = 109 - 20 = 89.

and to test if the values of a, b and c are correct:

a + b + c = 231

109 + 89 + 33 = 231

4 0

3 years ago

Find the equation of the circle in standard form for the given center (h, k) and radius r: (h, k) = (0, 0), r = 4

Ad libitum [116K]

Answer:

$x^2+y^2=16$

Step-by-step explanation:

The equation of a circle with center (h,k) and radius r is given by the formula;

$(x-h)^2+(y-k)^2=r^2$

Given (h,k)=(0,0) and r=4, we substitute the values to obtain;

$(x-0)^2+(y-0)^2=4^2$

The required equation is

$x^2+y^2=16$

8 0

3 years ago

Find the missing lengths of the sides

Kay [80]

Your answer would be A.

according to the 30°, 60°, 90° triangle rules,
side a would equal x
$side \: b \: would \: equal \: x \sqrt{3}$
and side c would equal 2x

4 0

3 years ago

Read 2 more answers

Evaluate the expression x-7, if x= 12. 19 6 05. (please help :( )​

Evaluate the expression x-7, if x= 12. 19 6 05. (please help :( )