Uually Cxpressions

The length of a rectangle is 5 more than the width. Find the length and width of a rectangle if the area of the rectangle is 36

harkovskaia [24]

Answer:

width = 4 in

length = 9 in

Step-by-step explanation:

To solve this problem, write an expression for the length and use the area of a rectangle formula.

The formula for area of a triangle is A = lw

"A" is the area.

"l" is the length.

"w" is the width.

"The length of a rectangle is 5 more than the width". It is represented in an expression:

l = w + 5 The width plus 5 is the length.

We also know the area is 36 in². Using information we know, replace variables in the formula for area of a rectangle.

Substitute l = w + 5 and A = 36

A = lw

36 = (w + 5)w Expand by multiplying w by the terms in the brackets.

36 = w² + 5w Since the equation is quadratic, make it equate to 0.

36 - 36 = w² + 5w - 36 Subtract 36 from both sides

0 = w² + 5w - 36 Factor this. Use group factoring, which is when you replace the middle term (5w) with two terms that add to make 5w, and multiply to get the last term (-36).

0 = w² + 9w - 4w - 36 9w times -4w is -36. They also add to get 5w.

0 = (w² + 9w) + (-4w - 36) Group the factors

0 = w(w + 9) + -4(w + 9) Take out the common factor in each group.

0 = w(w + 9) + -4(w + 9) Take out the new common factor binomial w+9

0 = (w + 9) (w - 4) Fully factored equation.

w + 9 = 0 w - 4 = 0 Set each binomial to equal 0.

w = -9 w = 4 Chose what makes sense to be the width.

The width cannot be a negative number, so the width is 4.

Since we know the width, we can find the length because the length is 5 more than the width.

l = w + 5

l = 4 + 5

l = 9 Length of the rectangle

Don't forget to include the units, inches.

Therefore the length is 9 inches and the width is 4 inches.

8 0

2 years ago

A bank advertises that it compounds money quarterly and that it will take Double your money in 10 years. what is the interest-ra

S_A_V [24]

The interest rate is 6.992%, if a bank advertises that it compounds money quarterly and that it will take Double your money in 10 years.

Step-by-step explanation:

The given is,

Compounds money quarterly

Double your money in 10 years

Step:1

Formula to calculate future investment with compounded quarterly,

$A =P(1+\frac{r}{n} )^{nt}$ ...............................(1)

Where, A - Future amount

P - Initial investment\

r - Rate of interest

n - No. of compounding in a year

t - No. of years

Step:2

Let, P = X

A = 2X ( Double your money )

From given, n - 4 ( for compounding quarterly )

t - 10 years

From equation (1)

$2X =X(1+\frac{r}{4} )^{(4)(10)}$

$\frac{2X}{X} =(1+\frac{r}{4} )^{(4)(10)}$

$2 =(1+\frac{r}{4} )^{40}$

Take root $40^{th}$ root on both side,

$\sqrt[40]{2} = (1+\frac{r}{4} )$

$1.017479692 = (\frac{4+r}{4} )$

$(1.017479692)(4) = (r+4)$

$4.06992=(r+4)$

$r = 4.06992 -4$

$r =( 0.06992)(100)$

r = 6.992 %

Result:

The interest rate is 6.992%, if a bank advertises that it compounds money quarterly and that it will take Double your money in 10 years.

3 0

2 years ago

Plz help on #3 ASAP!:)

masya89 [10]

Answer:

Step-by-step explanation:

4 0

2 years ago

Find the length of BD and EC. A D 9 8 B с BD = EC =

hammer [34]

I think BD is 16 and EC is 9. hope this helps

6 0

2 years ago

You asked 50 randomly chosen employees of a company how many books they read each month. the diagram show the results. there 600

podryga [215]

Answer:

About 432 people read at least one book per month.

Step-by-step explanation:

36/50 people read at least one book, multiply 36/50 by 12 to make the fraction 432/600.

8 0

2 years ago