Ask question

Ask question

All categories

4 years ago

15

I need help with this question

2 answers:

julia-pushkina [17]4 years ago

7 0

Hi there! The answer is 8 2 / 3

$\frac{3}{5} (r - 7) = 1$
First we need to get rid of the parentheses.

$\frac{3}{5} r - \frac{3}{5} \times \frac{7}{1} = 1$
$\frac{3}{5} r - \frac{21}{5} = 1$
$\frac{3}{5} r - 4\frac{1}{5} = 1$
Add 4 1/5 to both sides of the equation.

$\frac{3}{5} r =5 \frac{1}{5}$
Now divide both sides of the equation by 3 / 5 to find our answer.

$r = \frac{ 5 \frac{1}{5} }{ \frac{3}{5} } = 8 \frac{2}{3}$
Hence, our answer is 8 2 / 3

aliya0001 [1]4 years ago

7 0

This is a distributive problem, so 3/5 x r will give you 3/5r and 3/5 x -7 will equal -4.2
Your equation will look like 3/5r - 4.2=1
Now you have to solve this...
So you add 4.2 to both sides to get your equation to like like this,
3/5r -4.2=1
+4.2 =4.2 ----> 3/5r=5.2 now divide 5.2 by 3/5 to make r = 8.666

You might be interested in

Marcelo has 6 red marbles in his marble collection. The red marbles make up 12% of all the marbles. Please show your work and th

mixas84 [53]

Answer:

the answer is 50

Step-by-step explanation:

12 6 600 600

--------- * --------- = ------ ------- = 600/12=50
600 x 600 12

6 0

2 years ago

Law of sines: StartFraction sine (uppercase A) Over a EndFraction = StartFraction sine (uppercase B) Over b EndFraction = StartF

Vsevolod [243]

First of all, this problem is properly done with the Law of Cosines, which tells us

$a^2 = b^2 + c^2 - 2 b c \cos A$

giving us a quadratic equation for b we can solve. But let's do it with the Law of Sines as asked.

$\dfrac{\sin A}{a} = \dfrac{\sin B}{b} = \dfrac{\sin C}{c}$

We have c,a,A so the Law of Sines gives us sin C

$\sin C = \dfrac{c \sin A}{a} = \dfrac{5.4 \sin 20^\circ}{3.3} = 0.5597$

There are two possible triangle angles with this sine, supplementary angles, one acute, one obtuse:

$C_a = \arcsin(.5597) = 34.033^\circ$

$C_o = 180^\circ - C_a = 145.967^\circ$

Both of these make a valid triangle with A=20°. They give respective B's:

$B_a = 180^\circ - A - C_a = 125.967^\circ$

$B_o = 180^\circ - A - C_o = 14.033^\circ$

So we get two possibilities for b:

$b = \dfrac{a \sin B}{\sin A}$

$b_a = \dfrac{3.3 \sin 125.967^\circ}{\sin 20^\circ} = 7.8$

$b_o = \dfrac{3.3 \sin 14.033^\circ}{\sin 20^\circ} = 2.3$

Answer: 2.3 units and 7.8 units

Let's check it with the Law of Cosines:

$a^2 = b^2 + c^2 - 2 b c \cos A$

$0 = b^2 - (2 c \cos A)b + (c^2-a^2)$

There's a shortcut for the quadratic formula when the middle term is 'even.'

$b = c \cos A \pm \sqrt{c^2 \cos^2 A - (c^2-a^2)}$

$b = c \cos A \pm \sqrt{c^2( \cos^2 A - 1) + a^2}$

$b = 5.4 \cos 20 \pm \sqrt{5.4^2(\cos^2 20 -1) + 3.3^2}$

$b = 2.33958 \textrm{ or } 7.80910 \quad\checkmark$

Looks good.

6 0

3 years ago

Read 2 more answers

How do you calculate your gpa? (In Middle School).

Hatshy [7]

Look at your report card it should be on there somewhere

8 0

4 years ago

Factorise : a^2+4a-60 Step by Step

NARA [144]

Answer:

Step-by-step explanation:

Sum = 4

Product = -60

Factors = 10 , -6

a² + 4a - 60 = <u>a² + 10a</u> - 6a + (-6) * 10

=a(a + 10) - 6(a +10)

= (a +10) (a -6 )

6 0

4 years ago

What was the total cost of the ticket?

Vilka [71]

What ticket specifically are you talking about?

3 0

3 years ago