All categories

2 years ago

A boy rides his bike at a speed of 28 miles per hour. How

Mathematics

1 answer:

sergejj [24]2 years ago

6 0

Answer:

About 4 hours.

Step-by-step explanation:

Let's set up a proportion and cross multiply.

$\frac{28 miles}{1 hour} = \frac{120 miles}{x}$

Cross multiply.

120 = 28x

Divide by 28 on both sides.

= 4.28571428571

Round this to the nearest whole number, which is just 4. The answer is about 4 hours.

You might be interested in

Find the area of the composite shape shown below

Nata [24]

Let me guess it's 15

4 0

3 years ago

Help pleaseee:)))) <br> If x equals -4, what does -x equal???

Citrus2011 [14]

I would say it equals 4 because if x=-4 than -x should equal 4 i may be wrong though

5 0

2 years ago

4b - 5 + (-a-3) i = 7 * 8i

Rudik [331]

Answer:

Simplifying

4b + -5 + (-1a + -3) * i = 7 + -8i

Reorder the terms:

4b + -5 + (-3 + -1a) * i = 7 + -8i

Reorder the terms for easier multiplication:

4b + -5 + i(-3 + -1a) = 7 + -8i

4b + -5 + (-3 * i + -1a * i) = 7 + -8i

Reorder the terms:

4b + -5 + (-1ai + -3i) = 7 + -8i

Reorder the terms:

-5 + -1ai + 4b + -3i = 7 + -8i

Solving

-5 + -1ai + 4b + -3i = 7 + -8i

Solving for variable 'a'.

Move all terms containing a to the left, all other terms to the right.

Add '5' to each side of the equation.

-5 + -1ai + 4b + 5 + -3i = 7 + 5 + -8i

Reorder the terms:

-5 + 5 + -1ai + 4b + -3i = 7 + 5 + -8i

Combine like terms: -5 + 5 = 0

0 + -1ai + 4b + -3i = 7 + 5 + -8i

-1ai + 4b + -3i = 7 + 5 + -8i

Combine like terms: 7 + 5 = 12

-1ai + 4b + -3i = 12 + -8i

Add '-4b' to each side of the equation.

-1ai + 4b + -4b + -3i = 12 + -4b + -8i

Combine like terms: 4b + -4b = 0

-1ai + 0 + -3i = 12 + -4b + -8i

-1ai + -3i = 12 + -4b + -8i

Add '3i' to each side of the equation.

-1ai + -3i + 3i = 12 + -4b + -8i + 3i

Combine like terms: -3i + 3i = 0

-1ai + 0 = 12 + -4b + -8i + 3i

-1ai = 12 + -4b + -8i + 3i

Combine like terms: -8i + 3i = -5i

-1ai = 12 + -4b + -5i

Divide each side by '-1i'.

a = -12i-1 + 4bi-1 + 5

Simplifying

a = -12i-1 + 4bi-1 + 5

Reorder the terms:

a = 5 + 4bi-1 + -12i-1

4 0

2 years ago

Read 2 more answers

Solve y=-3x² + 4.5x – 20<br> Use the Quadratic formula

statuscvo [17]

Answer:

$x=0.75 \pm 2.47067i$

Step-by-step explanation:

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

√-1 is imaginary number i

Step 1: Define

y = -3x² + 4.5x - 20

a = -3

b = 4.5

c = -20

Step 2: Substitute and Evaluate

$x=\frac{-4.5 \pm \sqrt{4.5^2-4(-3)(-20)} }{2(-3)}$

$x=\frac{-4.5 \pm \sqrt{20.25-240} }{-6}$

$x=\frac{-4.5 \pm \sqrt{-219.75} }{-6}$

$x=\frac{-4.5 \pm \sqrt{219.75}(\sqrt{-1} ) }{-6}$

$x=\frac{-4.5 \pm i\sqrt{219.75} }{-6}$

$x=\frac{4.5 \pm i14.824 }{6}$

$x=0.75 \pm 2.47067i$

7 0

3 years ago

An artist builds a sculpture out of metal and wood that weighs 14.9 kilograms.

Ira Lisetskai [31]

Answer:

Given is a sculpture that is built up of metal and wood, and the weight of this sculpture is 14.9 kilograms.

It says that three-fourth of the total weight is metal and says to find the weight of wooden part.

We can find the weight of metal part and then subtract it from the total weight to calculate the answer.

Step-by-step explanation:

Total weight = 14.9 kilograms.

Metal part = three-fourth of total weight =

Wooden part = 14.9 - 11.175 = 3.725 kilograms.

Hence, the wooden part is 3.725 kilograms.

8 0

2 years ago

Read 2 more answers