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2 years ago

13

HELP PLZ!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

2 answers:

Maurinko [17]2 years ago

5 0

Answer:

D. $x=-5,y=\frac{5}{4}$

Step-by-step explanation:

$\begin{bmatrix}5x+4y=-20\\ 5x+12y=-10\end{bmatrix}$

Subtract Equation 2 - Equation 1:

$5x+12y=-10\\-\\\underline{5x+4y=-20}\\8y=10$

Divide both sides by 8:

$\frac{8y}{8}=\frac{10}{8}$

$y=\frac{5}{4}$

Substitute $y=\frac{5}{4}$ into Equation 1:

$5x+4y=-20$

$5x+4\times \frac{5}{4}=-20$

$5x+5=-20$

Subtract 5 from both sides:

$5x+5-5=-20-5$

$5x=-25$

Divide both sides by 5:

$\frac{5x}{5}=\frac{-25}{5}$

$x=-5$

Bas_tet [7]2 years ago

4 0

Answer:

c

Step-by-step explanation:

You might be interested in

Solve for x. Show each step of the solution. Show all work. 4.5(8-x)+36-2.5(3x+24)=102

sergejj [24]

4.5(8 - x) + 36 = 102 - 2.5(3x + 24)

36 - 4.5x + 36 = 102 - 7.5x - 60

72 - 4.5x = 42 - 7.5x

-4.5x + 7.5x = 42 - 72

3x = - 30

x = -30/3

x = -10 <===

Hope this helps!

4 0

3 years ago

The axis of symmetry for the graph of the function is f(x) = x2 + bx + 10 is x = 6. What is the value of b?

joja [24]

Answer:

$b=-12$

Step-by-step explanation:

we have

$f(x)=x^{2}+bx+10$

we know that

The equation of a vertical parabola into vertex form is equal to

$y=a(x-h)^{2} +k$

where

(h,k) is the vertex of the parabola

and the axis of symmetry is equal to $x=h$

In this problem we have the axis of symmetry $x=6$

so

the x-coordinate of the vertex is equal to $6$

therefore

For $x=6+1=7$ -----> one unit to the right of the vertex

Find the value of $f(7)$

$f(7)=7^{2}+b(7)+10$

$f(7)=59+7b$

For $x=6-1=5$ -----> one unit to the left of the vertex

Find the value of $f(5)$

$f(5)=5^{2}+b(5)+10$

$f(5)=35+5b$

Remember that

$f(5)=f(7)$ ------> the x-coordinates are at the same distance from the axis of symmetry

so

$59+7b=35+5b$ ------> solve for b

$7b-5b=35-59$

$2b=-24$

$b=-12$

3 0

2 years ago

Read 2 more answers

How do you solve 7a- 17=4a+1

Dennis_Churaev [7]

Answer:

a = 6

Explanation:

7a − 17 = 4a + 1

Subtract 4a from both sides

7a − 17 − 4a = 4a + 1 − 4a

3a − 17 = 1

Add 17 to both sides

3a − 17 + 17 = 1 + 17

3a = 18

Divide both sides by 3

3a / 3 = 18 / 3

a = 6

5 0

3 years ago

Can someone help me with this question

Flura [38]

The answer is A or c I’m probs wrong

7 0

2 years ago

Kyra has a rock collection. When she puts her rocks into 2 equal plies, there are no rocks left over. When she puts her rocks in

Nat2105 [25]

Step-by-step explanation:

According to this description we need a number that can be divided by 2,3 and 4 since the amount of rocks can be described by a natural number. However if a number is divided by 4 it is divided by 2 as well since 2*2=4.

$\frac{x}{4} = \alpha \\ \frac{x}{2} = 2 \alpha$

If α is a natural number then 2*α is a natural number as well as the product of two natural numbers.

Which means that we need a number devided by 3 and 4.

The smallest number that fulfills this demand is 3*4=12.

Also any product of 12 with any natural number can be devided by 3, 4 and 2.

If the exercise asks for the numbers that are divided only by 2,3 and 4 these are:

${3}^{ \alpha } \times 12 \: and \: {4}^{ \alpha } \times 12 \: \\ where \: \alpha \: belongs \: to \: the \: set \: of \: all \: \\ natural \: numbers$

8 0

2 years ago