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3 years ago

Help i dont how to do this

Mathematics

1 answer:

IrinaK [193]3 years ago

4 0

What is it you are trying to do I can help if you just say it.

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Delia went to the market to buy 4.5 pounds of sliced fruit in a container.she paid with a 20 bill and a 5 bill and received 3.67

Goryan [66]

Answer:

<h2>One pound of the item will cost 4.74 bill</h2>

Step-by-step explanation:

In this problem, we are told that Delia bought 4.5 pounds of fruit

and paid with a toa total bill of 20+5= 25 bill

and also she received a change of 3.67

this means that the item she bought cost 25-3.67= 21.33bill

now if 4.5 pounds of items cost 21.33 bill

then 1 pound will cost Xbill

cross multiply and solve for Xbill

X= 21.33/4.5

X= 4.74 bill

One pound of the item will cost 4.74 bill

4 0

3 years ago

Solve for the roots in simplest form by completing the square <br> 6x^2+120x+2070=0

Kitty [74]

Answer:

Step-by-step explanation:

First, we can divide out the common factor, 6

$6x^2 + 120x + 2070 = 0\\x^2 + 20x + 345 = 0\\$

Now we complete the square

$(x^2 + 20x + (\frac{20}{2})^2) + 345 - (\frac{20}{2})^2\\(x^2 + 20x + 100) + 345 - 100\\(x+10)^2 + 245\\$

$(x+10)^2 = -245\\x + 10 = \sqrt{-245}\\x = i\sqrt{245} - 10\\x = -10 \pm i\sqrt{245}$

8 0

3 years ago

Help me with solution please =(

Slav-nsk [51]

$\huge \boxed{\mathfrak{Question} \downarrow}$

Factorise the polynomials.

$\large \boxed{\mathfrak{Answer \: with \: Explanation} \downarrow}$

$\sf \: b ^ { 2 } + 8 b + 7$

Factor the expression by grouping. First, the expression needs to be rewritten as b²+pb+qb+7. To find p and q, set up a system to be solved.

$\sf \: p+q=8 \\ \sf pq=1\times 7=7$

As pq is positive, p and q have the same sign. As p+q is positive, p and q are both positive. The only such pair is the system solution.

$\sf \: p=1 \\ \sf \: q=7$

Rewrite $\sf\:b^{2}+8b+7 \: as \: \left(b^{2}+b\right)+\left(7b+7\right)$ .

$\sf \: \left(b^{2}+b\right)+\left(7b+7\right)$

Take out the common factors.

$\sf \: b\left(b+1\right)+7\left(b+1\right)$

Factor out common term b+1 by using distributive property.

$\boxed{\boxed{ \bf \: \left(b+1\right)\left(b+7\right) }}$

__________________

$\sf \: 4 x ^ { 2 } + 4 x + 1$

Factor the expression by grouping. First, the expression needs to be rewritten as 4x²+ax+bx+1. To find a and b, set up a system to be solved.

$\sf \: a+b=4 \\ \sf ab=4\times 1=4$

As ab is positive, a and b have the same sign. As a+b is positive, a and b are both positive. List all such integer pairs that give product 4.

$\sf \: 1,4 \\ \sf 2,2$

Calculate the sum for each pair.

$\sf \: 1+4=5 \\ \sf \: 2+2=4$

The solution is the pair that gives sum 4.

$\sf \: a=2 \\ \sf b=2$

Rewrite $\sf4x^{2}+4x+1 as \left(4x^{2}+2x\right)+\left(2x+1\right)$ .

$\sf \: \left(4x^{2}+2x\right)+\left(2x+1\right)$

Factor out 2x in 4x² + 2x.

$\sf \: 2x\left(2x+1\right)+2x+1$

Factor out common term 2x+1 by using distributive property.

$\sf\left(2x+1\right)\left(2x+1\right)$

Rewrite as a binomial square.

$\boxed{ \boxed{\bf\left(2x+1\right)^{2}} }$

__________________

$\sf \: 5 n ^ { 2 } + 10 n + 20$

Factor out 5. Polynomial n² + 2n+4 is not factored as it does not have any rational roots.

$\boxed{\boxed{\bf5\left(n^{2}+2n+4\right)} }$

<u>___________</u>_______

$\sf \: m ^ { 3 } - 729$

Rewrite m³-729 as m³ - 9³. The difference of cubes can be factored using the rule: $a^{3}-b^{3}=\left(a-b\right)\left(a^{2}+ab+b^{2}\right)$ . Polynomial m²+9m+81 is not factored as it does not have any rational roots.

$\boxed{ \boxed{ \bf \: \left(m-9\right)\left(m^{2}+9m+81\right) }}$

__________________

$\sf \: x ^ { 2 } - 81$

Rewrite x²-81 as x² - 9². The difference of squares can be factored using the rule: $a^{2}-b^{2}=\left(a-b\right)\left(a+b\right)$ .

$\boxed{ \boxed{ \bf\left(x-9\right)\left(x+9\right) }}$

__________________

$\sf \: 15 x ^ { 2 } - 17 x - 4$

Factor the expression by grouping. First, the expression needs to be rewritten as 15x²+ax+bx-4. To find a and b, set up a system to be solved.

$\sf \: a+b=-17 \\ \sf \: ab=15\left(-4\right)=-60$

As ab is negative, a and b have the opposite signs. As a+b is negative, the negative number has greater absolute value than the positive. List all such integer pairs that give product -60.

$\sf \: 1,-60 \\ \sf 2,-30 \\ \sf3,-20 \\ \sf4,-15 \\ \sf5,-12 \\ \sf 6,-10$

Calculate the sum for each pair.

$\sf \: 1-60=-59 \\ \sf 2-30=-28 \\ \sf3-20=-17 \\ \sf4-15=-11 \\ \sf5-12=-7 \\ \sf6-10=-4$

The solution is the pair that gives sum -17.

$\sf \: a=-20 \\ \sf \: b=3$

Rewrite $\sf15x^{2}-17x-4$ as $\sf \left(15x^{2}-20x\right)+\left(3x-4\right)$ .

$\sf\left(15x^{2}-20x\right)+\left(3x-4\right)$

Factor out 5x in 15x²-20x.

$\sf \: 5x\left(3x-4\right)+3x-4$

Factor out common term 3x-4 by using distributive property.

$\boxed{\boxed{ \bf\left(3x-4\right)\left(5x+1\right) }}$

6 0

3 years ago

Read 2 more answers

Which conversion requires multiplication? Use the metric table to help answer the question.

frosja888 [35]

Any conversion that goes down to a smaller value

Ex: Kilometer to meter will be x1000
meter to centimenter is x100

BUT going up will be division
Meter to kilometer is /1000

6 0

3 years ago

Read 2 more answers

What is the number or numbers that occur most frequently in a set of data

Papessa [141]

Answer:

The answer to this is the mode

Step-by-step explanation:

The mode is the number that occurs most frequently in a set of date

ex (1,2,3,3,4) mode=3

4 0

3 years ago