Round off then estimate 18.9*5.2

natita [175]

1] y - 3x = -8
[2] y + 9x = 4

-3x + y = -8 9x + y = 4

Solve equation [2] for the variable y

[2] y = -9x + 4

// Plug this in for variable y in equation [1]

[1] (-9x+4) - 3x = -8
[1] - 12x = -12
// Solve equation [1] for the variable x

[1] 12x = 12

[1] x = 1
// By now we know this much :

y = -9x+4
x = 1
// Use the x value to solve for y

y = -9(1)+4 = -5

{y,x} = {-5,1}

7 0

2 years ago

Just 4 people who need helppp

Arturiano [62]

Answer:

1/2 ÷ 4 = 8

Step-by-step explanation:

Dividing fractions is as easy as pie. Flip the second and multiply.

1/2 ÷ 4 = 1/8

A whole number secretly has a 1 underneath, like this: 4/1

Flip the second number over to get 1/4, then multiply straight across.

$\frac{1}{2}$ × $\frac{1}{4}$ = $\frac{1}{8}$

Try to do the same for the other answers and see if they're right (they're not).

1/8 x 1/6 = 1/48

1/3 x 1/4 = 1/12

1/9 x 1/2 = 1/18

4 0

2 years ago

Read 2 more answers

Find the equation of the circle with a diameter whose end points are (-1,-2) and (-3,2)

Sergeeva-Olga [200]

Answer:

The equation of the circle with a diameter whose end points are (-1,-2) and (-3,2) is

$x^{2} +y^{2}+4x-1=0$

Step-by-step explanation:

<u>Explanation:</u>-

<u>Step 1:</u>-

The equation of the circle having center and radius is

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

here center is (h,k) and radius is r

Given diameter whose end points are (-1,-2) and (-3,2)

The diameter of the circle is passing through the center of the circle

so center of the circle = midpoint of two end points

$(\frac{-1 +(-3) }{2} ,\frac{-2+2 }{2} )$

$(-2,0)$

therefore center (h,k) = (-2,0)

we have to find the radius of the circle

the radius of the circle = the distance from center to the one end point

i.e., C P = r

Given one end point is P(-3,2) and center C(-2,0)

The distance formula of two points are

$\sqrt{(x_{2}-x_{1} ) ^{2}+ (y_{2}-y_{1} ) ^{2}}$

$r=\sqrt{{(-3)-(-1) ) ^{2}+ (2-(-2)) ^{2}}$

$r=\sqrt{5}$

<u>Step 3</u>:-

center (h,k) = (-2,0) and

radius $r=\sqrt{5}$

The standard form of circle equation

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

$(x-(-2))^2+(y-0)^2=\sqrt{5} ^2$

on simplification is

$x^{2} +y^{2}+4 x-1=0$

5 0

2 years ago

To get from his house to the lecture hall at school, Lin walked west 651 feet. After class, he walked northeast 910 feet to the

Ahat [919]

The general direction that Lin walked from the gym to his house is; B: Lin walked southwest, creating an obtuse triangle.

<h3>How to interpret distance bearing?</h3>

We are given;

Distance between the lecture hall and gym = 910 feet.

Distance between the gym and Lin apostrophe's house = 615 feet.

Distance between the lecture hall and Lin apostrophe's house = 651 feet.

Now, since this 3 distances form a triangle and the 3 distances are unequal, then we can call it an obtuse triangle since he walked west and then walked northwest.

Now, since he walked back to his house from the gym, we can say that he walked southwest if we picture the bearing of his first two directions.

Read more about Distance Bearing at; brainly.com/question/22719608

#SPJ1

4 0

1 year ago

Suppose that 8% of the general population has a disease and that the test for the diesease is accurate 70% of the time. What is

balu736 [363]

Answer:

P = 0.332

Step-by-step explanation:

The probability of having the disease is 0.08

The probability that the test predicts with accuracy is 0.7.

We need to find the probability that the test positive for the disease.

Several cases may occur.

Case 1.

You have the disease and the test predicts it accurately

$P_1 = 0.08(0.7) = 0.056$

Case 2

You do not have the disease and the test predicts that you have it

$P_2 = 0.92(0.3) = 0.276$

Then the probability that the test predicts that you have the disease is the union of both probabilities P1 and P2

$P = P_1 + P_2\\\\P = 0.056 + 0.276\\\\P = 0.332$

8 0

2 years ago