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2 years ago

Find the solution to the following system of equations using substitution or elimination

Mathematics

1 answer:

Serggg [28]2 years ago

7 0

Answer:

D. (2,-3)

Step-by-step explanation:

if you substitute 2 for the x value and -3 for the y value in both equations, it works out.

instead of y=3x-9 it would be -3=3(2)-9.

you solve and get -3=-3, so it's a solution.

and instead of y=-2x+1 it would be -3=2(2)+1. after solving it, you would get -3=-3 again, so it works for both equations.

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Find the missing dimension. Use the scale 1:5

MrRissso [65]

Answer: 1m

Step-by-step explanation:

since model is 20cm, a 1:5 scale means the actual is 5x as big. since 20cm x 5 is 100 cm and 1m is 100 cm, the answer in the box should be 1.

4 0

1 year ago

The population of a species of rabbit triples every year. This

jok3333 [9.3K]

Answer:

"4" represents that there are 4 rabbit in the beginning.

Step-by-step explanation:

Given that the population of a species of rabbit triples every year. This

can be modeled by function $f\left(x\right)=4\left(3\right)^x$ and $f(5) = 972$ .

Now we need to find about what does the 4 represent in the given function.

We know that exponential function is given by $f\left(x\right)=a\left(b\right)^x$ . Where "a" represents the initial amount.

we have a=4 in given function $f\left(x\right)=4\left(3\right)^x$ .

So that means "4" represents that there are 4 rabbit in the beginning.

3 0

2 years ago

If a wheelchair-marathon racer moving at 13.1 miles per hour expends energy at a rate of 645 calories per hour, how much energy

Anna71 [15]

Answer:

$1290$ calories

Step-by-step explanation:

Given: The racer moves at $13.1$ miles per hour expends energy at a rate of $645$ calories per hour.

To find: Energy in calories, required to complete a marathon race $26.2$ miles at this pace.

Solution: We have,

The racer moves at $13.1$ miles per hour.

The racer expends energy at a rate of $645$ calories per hour.

So, energy expended while moving $13.1$ miles $=645$ calories.

Now, energy expended while moving $1$ mile $=\frac{645}{13.1}$ calories.

So, energy expended while moving $26.2$ miles $=\frac{645}{13.1}\times 26.2=645\times 2=1290$ calories.

Hence, $1290$ calories of energy is required to complete a marathon race $26.2$ miles at this pace.

6 0

3 years ago

A pencil consists of a cone stacked on top of a cylinder. The diameter of the cylindrical base of the pencil is 10 mm and the he

11Alexandr11 [23.1K]

Answer:

790π

Step-by-step explanation:

We are given;

Diameter of cylinder;d = 10 mm

So, radius;r = 10/2 = 5 mm

Height of cylinder;h = 70mm

Surface area of cylinder is given by the formula; S.A = 2πr² + 2πrh

Plugging in the relevant values, we have;S.A = 2π(5)² + 2π(5)(70)

S.A = 50π + 700π

S.A = 750π

Now, because one base of the cylinder is hidden as the cone is stacked on that face, we will deduct the area of that base face;

Thus, Surface area = 750π - π(5)² = 750π - 25π = 725π

For the cone,

Height;h = 12mm

Since this is stacked directly on the cylinder, it will have the same radius. Thus; radius;r = 5mm

Now,formula for surface area of cone is;

S.A = πr² + πrL

Where L is slant height.

We can use pythagoras theorem to get L.

So, L² = r² + h²

L = √r² + h²

L = √(5² + 12²)

L = √(25 + 144)

L = √169

L = 13

So, S.A of cone = π(5)² + (π×5×13)

S.A = 25π + 65π = 90π

Similar to what was done to the Cylinder, since the circular base of the cone is stacked on the cylinder, we will deduct the surface area of that base as it is hidden.

So, S.A is now = 90π - π(5)²

= 90π - 25π = 65π

Thus,total surface area of the pencil = 725π + 65π = 790π

7 0

3 years ago

Read 2 more answers

28 4/7 simplify chang percent to a fractiom

Tresset [83]

4/7 to a percent is about 57 percent.

6 0

2 years ago

Read 2 more answers

Find the solution to the following system of equations using substitution or elimination​

Find the solution to the following system of equations using substitution or elimination