All categories

2 years ago

It takes 45 minutes for 4 people to paint 5 walls. How many minutes does it take 6 people to paint 4 walls?

1 answer:

3 0

45/5 = 9minutes/wall = 1wall/9minute/4 people = (1/36) per minute per person

(1/36)*6 = 1/6 wall per minute per 6 people * 24 = 4 walls in 24 minutes

24 Minutes total

You might be interested in

Z to the power of 2 =1

stiv31 [10]

That would be written as:

$z^{2} = 1$

And the step-by-step equation would be:

$z^{2} = 1$ → we take the 2 to the right side of the equation and do the IO*

$z = \sqrt{1}$ →we solve for $\sqrt{1}$

$z = 1$ → final answer

*Ps - IO is not an existing term and stands for inverse operation. In this case, because when we take to 2 to the right side of the equation (the 2 is a power) it'll have to turn into a square root (because exponents and roots are inverse operations)

Hope it helped,

BioTeacher101

3 0

3 years ago

Which of the following expressions is equivalent to a3 + b3?

lubasha [3.4K]

ANSWER
${a}^{3} + {b}^{3} = (a + b)( {a}^{2 } - ab + {b}^{2} )$

EXPLANATION

To find the expression that is equivalent to
${a}^{3} + {b}^{3}$
we must first expand
${(a + b)}^{3}$
Then we rearrange to find the required expression.

So let's get started.

${(a + b)}^{3} = (a + b) {(a + b)}^{2}$

We expand the parenthesis on the right hand side to get,

${(a + b)}^{3} = (a + b) ( {a}^{2} + 2ab + {b}^{2} )$

We expand again to obtain,

${(a + b)}^{3} = {a}^{3} + 3 {a}^{2}b + 3a {b}^{2} + {b}^{3}$

Let us group the cubed terms on the right hand side to get,

${(a + b)}^{3} = {a}^{3} + {b}^{3} + 3 {a}^{2}b + 3a {b}^{2}$

${(a + b)}^{3} = {a}^{3} + {b}^{3} + 3ab (a+ b)$

We make the cubed terms the subject,

${(a + b)}^{3} - 3ab (a+ b) = {a}^{3} + {b}^{3}$

We factor to get,

$(a + b)({(a + b)}^{2} - 3ab ) = {a}^{3} + {b}^{3}$

We expand the bracket on the left hand side to get,

$(a + b)( {a}^{2} + 2ab + {b}^{2} - 3ab ) = {a}^{3} + {b}^{3}$

We finally simplify to get,

$(a + b)( {a}^{2} - ab + {b}^{2} ) = {a}^{3} + {b}^{3}$

5 0

3 years ago

Read 2 more answers

Need help with option 1 or 2

Pani-rosa [81]

Option 2.

1. Simplify 7 + (12 - 9) + 7 × 3(8 - 5)

According to the Order of Operations, contents of parentheses are evaluated first. This gives

... 7 + 3 + 7 × 3 × 3

Then multiplication and division are performed left to right.

... = 7 + 3 + 21 × 3

... = 7 + 3 + 63

Followed by addition and subtraction left to right.

... = 10 + 63

... = 73

A Google search box can be relied upon to do the operations in the correct order.

_____

2. When the expression is rewritten, a different result is obtained. This is because the operations indicated by the second set of parentheses are altered.

... (7 + 12) - 9 + (7 × 3)8 - 5

... = 19 - 9 + 21 × 8 - 5

... = 19 - 9 + 168 - 5

... = 10 + 168 - 5

... = 178 - 5

... = 173

In the first expression, both +8 and -5 are multiplied by 21. In the rewritten expression, only +8 is multiplied by 21.