What is the radius of this circle if the circumference is 18 pie cm?

!!! HELP ME !!!

antoniya [11.8K]

Answer:

DHGB

Step-by-step explanation:

Let's start with 1.

The equation is in standard form (ax+by=c): -4x+2y=8

we'll put it into slope intercept form.

Add 4x onto both sides

2y=4x+8

divide by 2

y=2x+4

Parallel lines have the same slope, but a different y intercept. (the line parallel to this one will have a slope of 2 but a y intercept different from +4)

Looking at the answer choices, the only choice with a slope of 2 is D (y=2x-5)

So the answer to 1 is D

Now 2.

we're given 3 points. One of the points crosses the y axis, which is the y intercept. In this case, the line crosses the point (0,3)

That means the y intercept of the line is (0,3)

here's the line so far:

y=mx+3 (m is a placeholder for the slope)

when given a graph, we can use rise/run. Starting from the point (3,2), we can move 3 spaces to the left, and one up.

In a graph, if you move to the left or downwards, it's a negative move. If you move up or to the right, it's a positive move.

Since we went 1 space up (rise) and 3 spaces to the left, (run) the slope is -1/3

So the line is y=-1/3x+3

Perpendicular lines are negative and reciprocal. If you multiply their slopes, they will equal -1. Their y intercepts don't matter at all.

So to find the slope, we can use this equation.

-1/3m=-1

multiply by -3 on both sides

m=3

Looking at the answer choices, H is the only answer with a slope of 3. So the answer to 2 is H.

Now, 3

You can do the graph method like above for 2, but I'll just calculate the slope.

We're given two points, (-1,-2) and (0,2)

the formula for slope is (y2-y1)/(x2-x1)

we can label the points.

x1=-1

y1=-2

x2=0

y2=2

now, substitute into the equation.

m=(2--2)/(0--1)

m=4/1

the slope is 4.

Now let's use point slope form, which is y-y1=m(x-x1)

once again, sub. into the equation.

y+2=4(x+1)

do distributive prop

y+2=4x+4

subtract by 2

y=4x+2

As said above, parallel lines have the same slope.

Looking at the answer options, G also has the slope of 4

so the answer to 3 is G

Finally, #4

Equation: 3x+y=1

subtract 3x from both sides

y=-3x+1

As said above, perpendicular lines have slopes that multiply to equal -1.

-3m=-1

multiply by -1/3

m=1/3

so the slope of the line will be 1/3.

Looking at the answer options, B also has a slope of 1/3.

So the answer to 4 is B

The code is DHGB

Hope this helps!

4 0

2 years ago

Lin and Andre start walking toward each other at the same time from opposite ends of a 22 mile walking trail. I am to lazy to ty

notka56 [123]

Answer:

2 hours- 5 miles, 6 miles, 13 miles

3 Hours- 7.5, 9, 9.5

4 hours- 10, 12, 6

Step-by-step explanation:

I think it might be wrong but I did my best sorry!

4 0

2 years ago

Read 2 more answers

Which expressions are completely factored? Select each correct answer. 30a6−24a2=3a2(10a4−8) 16a5−20a3=4a3(4a2−5) 12a3+8a=4(3a3+

irinina [24]

When factoring an expression, we need to identify the Greatest Common Factor of the expression (GCF). By definition, GCF is the product of prime factors involved with its Lowest Exponent.

We need to divide each term by the GCF to get the expression inside the parenthesis.

$30a^6-24a^2\\ GCF\; is \; 6a^2\\ \\ 30a^6-24a^2=6a^2(\frac{3a^6}{6a^2} -\frac{24a^2}{6a^2} )=6a^2(5a^4-4)\\ ---------------------\\ \\ 16a^5-20a^3\\ GCF \; is \; 4a^3\\ \\ 16a^5-20a^3=4a^3(\frac{16a^5}{4a^3} -\frac{20a^3}{4a^3})=4a^3(4a^2-5) \\ ---------------------\\ \\ 12a^3+8a\\ GCF \; is \; 4a\\ \\ 12a^3+8a=4a(\frac{12a^3}{4a}+\frac{8a}{4a})=4a(3a^2+2)\\ ---------------------\\ 24a^4+18\\GCF \; is \; 6\\\\24a^4+18=6(\frac{24a^4}{6} +\frac{18}{6})=6(4a^4+3) \\ ---------------------$