Can someone help me in number 3 I’m not shure how to do it

James has $325 in his savings account. He spends $28 a week. How many, w, weeks until he has $157 left in his account?

otez555 [7]

Answer:

6 weeks

Step-by-step explanation:

Total savings= $325

For every week, his total savings decrease by $28.

Let's form an expression for the amount of money left in his account after w weeks.

325 -28w= 157

28w= 325 -157

28w= 168

Divide by 28 on both sides:

w= 168 ÷28

w= 6

Thus, there are 6 weeks until he has $157.

3 0

2 years ago

Roberto rowed 20 miles downstream in 2.5 hours. The trip back, however, took him 5 hours. Find the rate that Roberto rows in sti

almond37 [142]

Answer:

Roberto's speed in still water is 6 miles/hour and the river speed is 2 miles/hour

Step-by-step explanation:

Relative Speed

When a body is moving at a constant speed v, the distance traveled in a time t is:

$d=v.t$

When Roberto rows downstream, his speed in still water is added to the speed of the water, making it easier to travel the required distance.

When Roberto rows upstream, his speed in still water is affected by the speed of the water, both are subtracted and the required distance is covered in more time.

Let's call

x = Roberto's rowing speed in still water

y = Speed of the river current

The speed when rowing downstream is x+y, thus the distance traveled is

$d=(x+y).t_1$

Where t1=2.5 hours. Substituting values:

$20=(x+y)*2.5$

Rearranging, we find the downstream equation:

$2.5x+2.5y=20\qquad[1]$

The speed when rowing upstream is x-y, and the distance traveled is

$d=(x-y).t_2$

Where t2=5 hours. Substituting values:

$20=(x-y)*5$

Rearranging, we find the upstream equation:

$5x-5y=20\qquad[2]$

Multiplying [1] by 2:

$5x+5y=40$

Adding this equation to [2]:

$10x=60$

Solving:

$x=60/10=6$

Dividing [2] by 5:

$x-y=4$

Solving for y

$y=x-4=6-4=2$

Thus, Roberto's speed in still water is 6 miles/hour and the river speed is 2 miles/hour

3 0

3 years ago

Please help me solve this problem ASAP

DiKsa [7]

$\bold{\huge{\blue{\underline{ Solution }}}}$

<h3>Given :-</h3>

The right angled below is formed by 3 squares A, B and C
The area of square B has an area of 144 inches ²
The area of square C has an of 169 inches ²

We have to find the area of square A?

<h3>Let's Begin :- </h3>

The right angled triangle is formed by 3 squares

We have, 

Area of square B is 144 inches²
Area of square C is 169 inches²

We know that,

$\bold{ Area \: of \: square = Side × Side }$

Let the side of square B be x

Subsitute the required values,

$\sf{ 144 = x × x }$

$\sf{ 144 = x² }$

$\sf{ x = √144}$

$\bold{\red{ x = 12\: inches }}$

Thus, The dimension of square B is 12 inches

Area of square C = 169 inches

Let the side of square C be y

Subsitute the required values,

$\sf{ 169 = y × y }$

$\sf{ 169 = y² }$

$\sf{ y = √169}$

$\bold{\green{ y = 13\: inches }}$

Thus, The dimension of square C is 13 inches.

It is mentioned in the question that, the right angled triangle is formed by 3 squares

The dimensions of square be is x and y

Let the dimensions of square A be z

<h3>Therefore, By using Pythagoras theorem, </h3>

The sum of squares of base and perpendicular height equal to the square of hypotenuse

That is,

$\bold{\pink{ (Perpendicular)² + (Base)² = (Hypotenuse)² }}$

Here, 

Base = x = 12 inches
Perpendicular = z
Hypotenuse = y = 13 inches

Subsitute the required values,

$\sf{ (z)² + (x)² = (y)² }$

$\sf{ (z)² + (12)² = (169)² }$

$\sf{ (z)² + 144 = 169}$

$\sf{ (z)² = 169 - 144 }$

$\sf{ (z)² = 25}$

$\bold{\blue{ z = 5 }}$

Thus, The dimensions of square A is 5 inches

<h3>Therefore,</h3>

Area of square

$\sf{ = Side × Side }$

$\sf{ = 5 × 5 }$

$\bold{\orange{ = 25\: inches }}$

Hence, The area of square A is 25 inches.

6 0

2 years ago

GIVING BRAILEST Describe a situation that the equation could represent g+3 _____ =15 6

krek1111 [17]

Answer:

g=153

Step-by-step explanation:

i hope this helped...

6 0

2 years ago

Using standard algorithm what does 82 times 18 equal

VashaNatasha [74]

82 times 18 would add up to 1,476. Hope this helped.

6 0

3 years ago

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