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SVETLANKA909090 [29]

3 years ago

10

What is -40+7r=-5(8+5r)

1 answer:

Nuetrik [128]3 years ago

3 0

Answer:

r= -40/9 or r=-4 4/9

Step-by-step explanation:

You're welcome :)

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Someone help me plsss which one do I choose

True [87]

Answer:

Ans: 0.0014

Step-by-step explanation:

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7 0

3 years ago

The shardze family is planning A car trip to Atlanta Georgia which is 279 miles from their home they plan to drive at an average

Gnoma [55]

They are going 279 miles at a rate of 62 mph.

time = distance / speed
time = 279/62
time = 4.5 hrs...or (4 hrs 30 minutes)

plus they plan on a 45 minute lunch...
4 hrs and 30 minutes + 45 minutes = 4 hrs and 75 minutes =
5 hrs 15 minutes. So they need 5 hrs and 15 minutes to get there...and they want to be there by 3.

So they will have to leave at : 9:45 <==

4 0

3 years ago

X= 2 and y = 4, then -X-XY

Fed [463]

Answer:

-10

Step-by-step explanation:

= -X - XY

= -2 - 2×4

= -2 - 8

= -10

therefore, -X - XY = -10

5 0

2 years ago

Read 2 more answers

Which of the following is a solution to 2cos2x − cos x − 1 = 0?

Pavel [41]

Answer:

Option A is correct.

Solution for the given equation is, $x = 0^{\circ}$

Step-by-step explanation:

Given that : $2\cos^2x -\cos x -1 =0$

Let $\cos x =y$

then our equation become;

$2y^2-y-1= 0$ .....[1]

A quadratic equation is of the form:

$ax^2+bx+c =0$ .....[2] where a, b and c are coefficient and the solution is given by;

$x = \frac{-b\pm \sqrt{b^2-4ac}}{2a}$

Comparing equation [1] and [2] we get;

a = 2 b = -1 and c =-1

then;

$y = \frac{-(-1)\pm \sqrt{(-1)^2-4(2)(-1)}}{2(2)}$

Simplify:

$y = \frac{ 1 \pm \sqrt{1+8}}{4}$

or

$y = \frac{ 1 \pm \sqrt{9}}{4}$

$y = \frac{ 1 \pm 3}{4}$

or

$y = \frac{1+3}{4}$ and $y = \frac{1 -3}{4}$

Simplify:

y = 1 and $y = -\frac{1}{2}$

Substitute y = cos x we have;

$\cos x = 1$

⇒ $x = 0^{\circ}$

and

$\cos x = -\frac{1}{2}$

⇒ $x = 120^{\circ} \text{and} x = 240^{\circ}$

The solution set: $\{0^{\circ}, 120^{\circ} , 240^{\circ}\}$

Therefore, the solution for the given equation $2\cos^2x -\cos x -1 =0$ is, $0^{\circ}$

8 0

3 years ago

Read 2 more answers

Factoring Quadratics - Please help; will mark Brainliest!

rosijanka [135]

Answer:

1) x = -1 or x = -10 (either of them are both correct)

2) x = 3 or x = -5

Step-by-step explanation:

Let's solve your equation step-by-step.

x2 + 11x + 10 =0

Step 1: Factor left side of equation.

(x + 1)(x + 10) = 0

Step 2: Set factors equal to 0.

x + 1 = 0 or x +10 = 0

x = −1 or x = −10

Answer:

x = −1 or x = −10

2x^2 + 4x − 30 = 0

Answer:

x = 3 or x = −5

5 0

3 years ago