PLZ HELP ME ILL MARK BRAINLIETS

mojhsa [17]

Assumin we solving for the intersection or solution

elimination, ya

eliminate y's

multiply firs equation by 2 and add to 2nd

we get
6x+2y=16
-x-2y=-10 +
5x+0y=6

5x=6
divide both sides by 5
x=6/5

sub back
-x-2y=-10
-6/5-2y=-10
times both sides by 5
-6-10y=-50
add 6 to both sides
-10y=-44
divide both sides by -10
y=44/10
y=22/5

(x,y)
$(\frac{6}{5},\frac{22}{5})$
or
(1.2,4.4)

5 0

3 years ago

Find the slope and y-intercept for x + 3y=3

Zarrin [17]

By definition, the Slope-Intercept Form of the equation of a line is:

$y=mx+b$

Where "m" is the slope and "b" is the y-intercept.

Then, to find the slope and the y-intercept of the line given in the exercise, you only need to solve for "y", in order to write the equation in Slope-Intercept Form:

$\begin{gathered} x+3y=3 \\ 3y=-x+3 \\ \\ y=\frac{-1}{3}x+\frac{3}{3} \\ \\ y=-\frac{1}{3}x+1 \end{gathered}$

Now you can identify that the slope is:

$m=-\frac{1}{3}$

And the y-intercept is:

$b=1$

Therefore, the answer is:

$\begin{gathered} m=-\frac{1}{3} \\ \\ b=1 \end{gathered}$

5 0

9 months ago

Find the sum of all natural numbers between 25 and 210 which are either divisible by 3 or divisible by 4? Please let me know I

Ray Of Light [21]

Let S be the sum of the integers 25-210:

S = 25 + 26 + 27 + … + 208 + 209 + 210

Let S₃, S₄, and S₁₂ denote the sums of the integers in S that are multiples of 3, 4, or 12, respectively. We'll also count how many terms each sum involves; it'll be useful later.

S₃ = 27 + 30 + 33 + … + 204 + 207 + 210 … … … (62 terms)

S₃ = 3 (9 + 10 + 11 + … + 68 + 69 + 70)

S₄ = 28 + 32 + 36 + … + 200 + 204 + 208 … … … (46 terms)

S₄ = 4 (7 + 8 + 9 + … + 50 + 51 + 52)

S₁₂ = 36 + 48 + 60 + … + 180 + 192 + 204 … … … (15 terms)

S₁₂ = 12 (3 + 4 + 5 + … + 15 + 16 + 17)

Let's look at S₃ :

S₃ = 3 (9 + 10 + 11 + … + 68 + 69 + 70)

By reversing the order of the sum, we get

S₃* = 3 (70 + 69 + 68 + … + 11 + 10 + 9)

Of course S₃ = S₃*, I'm just calling it something else temporarily. Notice that every term in the same position of either sum adds up the same number.

9 + 70 = 79

10 + 69 = 79

11 + 68 = 79

and so on. Then

S₃ + S₃* = 3 (79 + 79 + 79 + … + 79 + 79 + 79)

or

2S₃ = 3 × 62 × 79 ==> S₃ = 7,347

We can compute the other two sums in the same way.

S₄ = 4 (7 + 8 + 9 + … + 50 + 51 + 52)

S₄* = 4 (52 + 51 + 50 + … + 9 + 8 + 7)

==> 2S₄ = 4 × 46 × 59 ==> S₄ = 5,428

S₁₂ = 12 (3 + 4 + 5 + … + 15 + 16 + 17)

S₁₂* = 12 (17 + 16 +15 + … + 5 + 4 + 3)

==> 2S₁₂ = 12 × 15 × 20 ==> S₁₂ = 1,800

Then the sum you want is

S₃ + S₄ - S₁₂ = 10,975

We subtract S₁₂ because each of its terms is counted twice (once in S₃ and again in S₄).

6 0

2 years ago

Arithmetic sequences et sn} be an arithmetic sequence that starts with an initial index of 0. The initial term is 3 and the comm

navik [9.2K]

Answer:

(a) The value of $s_z$ is (z+1)(3-z).

(b) The next term in the sequence is -2.

Step-by-step explanation:

(a)

It is given that arithmetic sequence that starts with an initial index of 0.

The initial term is 3 and the common difference is -2.

$a_0=3$

$d=-2$

We need to find the value of $s_z$ .

$s_z=\sum_{n=0}^{n=z}(a+nd)$

where, a is initial term and d is common difference.

$s_z=\sum_{n=0}^{n=z}(3-2n)$

The sum of an arithmetic sequence with initial index 0 is

$s_n=\frac{n+1}{2}[2a+nd]$

where, a is initial term and d is common difference.

Substitute n=z, a=3 and d=-2 in the above formula.

$s_z=\frac{z+1}{2}[2(3)+z(-2)]$

$s_z=\frac{z+1}{2}[2(3-z)]$

$s_z=(z+1)(3-z)$

Therefore the value of $s_z$ is (z+1)(3-z).

(b)

The given arithmetic sequence is

7, 4, 1, ...

We need to find the term in the sequence.

In the given arithmetic sequence the first term is

$a=7$

The common difference of the sequence is

$d=a_2-a_1\Rightarrow 4-7=-3$

The first term is 7 and common difference is -3.

Add common difference in last given term, i.e., 1, to find the next term of the sequence.

$1+(-3)=1-3=-2$

Therefore the next term in the sequence is -2.

3 0

3 years ago

25 POINTS AND BRAINLIEST

kondor19780726 [428]

Answer:

4.24 hours

Step-by-step explanation:

Irina can paint 1/9 of a room in 1 hour since she can paint a room in 9 hours. 1/9x, where x is the number of hours she works and 1/9 of a room per hour is her speed, would be her part of the calculation.

Paulo can paint 1/8 of a room in 1 hour since he can paint an entire room in 8 hours. 1/8x, where x is the number of hours he works and 1/8 of a room per hour is his speed, would be his part of the equation.

1/9x + 1/8x = 1 (Irina's portion of the room plus Paulo's portion of the room equals one complete room) would be the equation.

Look for a denominator that has the same value as the numerator. Both 9 and 8 split evenly into 72 as the initial number. We multiply the top of 1/9 by 8 to convert the fraction and get 8/72x because 9*8 = 72. We multiply the top of 1/8 by 9 to convert the fraction and get 9/72x because 8*9 = 72. We have 8/72x+9/72x=1 currently.

17/72x=1

÷ both sides by 17/72:

17/72x ÷ 17/72 = 1÷17/72

∴ x=1/1 * 72/17

∴ x=72/17= 4.24

8 0

1 year ago