All categories

3 years ago

How do I do 2/5÷(-10/7)

Mathematics

1 answer:

coldgirl [10]3 years ago

6 0

Answer:

Step-by-step explanation:

Reduce the expression, if possible, by cancelling the common factors.

Exact Form: 7/25 Decimal from 0.28

You might be interested in

Use triangle ABC drawn below & only the sides labeled. Find the side of length AB in terms of side a, side b & angle C o

Brrunno [24]

Answer:

$AB = \sqrt{a^2 + b^2-2abCos\ C}$

Step-by-step explanation:

Given:

The above triangle

Required

Solve for AB in terms of a, b and angle C

Considering right angled triangle BOC where O is the point between b-x and x

From BOC, we have that:

$Sin\ C = \frac{h}{a}$

Make h the subject:

$h = aSin\ C$

Also, in BOC (Using Pythagoras)

$a^2 = h^2 + x^2$

Make $x^2$ the subject

$x^2 = a^2 - h^2$

Substitute $aSin\ C$ for h

$x^2 = a^2 - h^2$ becomes

$x^2 = a^2 - (aSin\ C)^2$

$x^2 = a^2 - a^2Sin^2\ C$

Factorize

$x^2 = a^2 (1 - Sin^2\ C)$

In trigonometry:

$Cos^2C = 1-Sin^2C$

So, we have that:

$x^2 = a^2 Cos^2\ C$

Take square roots of both sides

$x= aCos\ C$

In triangle BOA, applying Pythagoras theorem, we have that:

$AB^2 = h^2 + (b-x)^2$

Open bracket

$AB^2 = h^2 + b^2-2bx+x^2$

Substitute $x= aCos\ C$ and $h = aSin\ C$ in $AB^2 = h^2 + b^2-2bx+x^2$

$AB^2 = h^2 + b^2-2bx+x^2$

$AB^2 = (aSin\ C)^2 + b^2-2b(aCos\ C)+(aCos\ C)^2$

Open Bracket

$AB^2 = a^2Sin^2\ C + b^2-2abCos\ C+a^2Cos^2\ C$

Reorder

$AB^2 = a^2Sin^2\ C +a^2Cos^2\ C + b^2-2abCos\ C$

Factorize:

$AB^2 = a^2(Sin^2\ C +Cos^2\ C) + b^2-2abCos\ C$

In trigonometry:

$Sin^2C + Cos^2 = 1$

So, we have that:

$AB^2 = a^2 * 1 + b^2-2abCos\ C$

$AB^2 = a^2 + b^2-2abCos\ C$

Take square roots of both sides

$AB = \sqrt{a^2 + b^2-2abCos\ C}$

6 0

3 years ago

For each sentence, write an equation.

Dafna11 [192]

A) x/6=9
Subtract 6 from both sides, x=3

B) x/-4=-3
Add 4 to both sides, x=1

C) x/-5=7
Add 5 to both sides, x=12

5 0

3 years ago

HELP I NEED HELP ASAP

jarptica [38.1K]

Answer:

Step-by-step explanation:

tsgsgsgs sorry if wrong

8 0

3 years ago

Read 2 more answers

What is 84/5 divided by 4 =

dangina [55]

THe answer is, $21/5$

And in decemal form it will be, $4.2$

5 0

3 years ago

I need help on this problem!?

nata0808 [166]

156/4=39 miles per gallon. 39*12 gallons is 468 miles, and 6 gallons is 234.

6 0

3 years ago

How do I do 2/5÷(-10/7)​

How do I do 2/5÷(-10/7)