Please help me with question 12 :(

The speed of boat in still water is 15km/hr if needs 4 more his to travel 63 km against the current of a river than it needs to

hram777 [196]

Answer:

$\frac{63}{15 - c} - \frac{63}{15 + c} = 4$

Step-by-step explanation:

The systems of equations are

Let us assume the rate of the current be c

Now actual speed against the current is (15 - c)

And, the actual speed with the current is (15 + c)

Here we applied the time formula i.e. distance by speed

Also the upstream time - downstream time = 4

Now the equations are

$\frac{63}{15 - c} - \frac{63}{15 + c} = 4$

5 0

2 years ago

An angle measured 10 degrees less than the measure of its complementary angle. Find the measure of both angles

Mazyrski [523]

Answer:

The measure of the angles are 40 degrees and 50 degrees

Step-by-step explanation:

Let

x ----> the measure of one angle in degrees

y ----> the measure of the complementary angle in degrees

we know that

If two angles are complementary, then their sum is equal to 90 degrees

so

$x+y=90$ ----> equation A

we have that

$x=y-10$ ----> equation B

Substitute equation B in equation A and solve for y

$(y-10)+y=90\\2y-10=90\\2y=100\\y=50$

Find the value of x

$x=50-10=40$

therefore

The measure of the angles are 40 degrees and 50 degrees

3 0

2 years ago

The function f(x) = is translated up 4 units. Which equation represents the translated function?

kkurt [141]

Answer:

The translated function can be written as:

y = f(x) + 4

3 0

2 years ago

Read 2 more answers

Sonia opened a savings account and then added the same amount to the savings account eyery week. After 5 weeks, her savings acco

Goryan [66]

Answer:

since Sonia saved 45$ in 5 weeks and 70$ in 10 weeks. we are to find the amount she saved up in x weeks.

let's make the amount y

so x= y

5 = 45 cross multiplying the values

we then have 45x= 5y

y= 7x

x=y

10=70

10x = 70y

y= 7x = y=5x+ 20, y = 20x+5

7 0

3 years ago

Which expression represents the area of the shaded region?

irina1246 [14]

Given:

A circle of radius r inscribed in a square.

To find:

The expression for the area of the shaded region.

Solution:

Area of a circle is:

$A_1=\pi r^2$

Where, r is the radius of the circle.

Area of a square is:

$Area=a^2$

Where, a is the side of the square.

A circle of radius r inscribed in a square. So, diameter of the circle is equal to the side of the square.

$a=2a$

So, the area of the square is:

$A_2=(2r)^2$

$A_2=4r^2$

Now, the area of the shaded region is the difference between the area of the square and the area of the circle.

$A=A_2-A_1$

$A=4r^2-\pi r^2$

$A=r^2(4-\pi )$

Therefore, the correct option is (a).

5 0

3 years ago