Mike is three times as old as his little sister, Mary. In 4 years, he will be twice as old as Mary. How old is Mary?

Answers

Answer 1

Answer: x-the age of Mike
y-the age of his sister

x=3y

x+4=2(y+4)
3y+4=2y+8
3y-2y=8-4
y=4 years

x=3*4=12 years

Answer 2

Answer: Mary: x yrs old
Mike: 3x yrs old

In four yrs:

Mary: x+4 yrs old
Mike: 3x+4 yrs old

As the text of task:

3x+4=2(x+4)
3x+4=2x+8
3x-2x=8-4
x=4

Mary is 4 yrs old

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What is the equation of the line through point (1, 5) and perpendicular to a line with a slope of 2/5?

Answers

Point slope formula is
y-y1=m(x-x1)
points are (x1,y1) (1,5) m=2/5
y-5=2/5(x-1)

a student has some $1 and $5 bills in his wallet. He has a total of 13 bills that are worth $33. How many of each type of bill does he have?

Answers

Answer: The number $1 bills is 8 and the number of $5 bills is 8.

Step-by-step explanation:

Let x denotes $1 bills and y be denotes $5 bills.

Then , we have the following equations :-

$x+y=13-------(1)\n\nx+5y=33-------(2)$

Subtracting equation (1) from (2), we get

$4y=33-13=20\n\n\Rightarrow y=\frac{20}[4}=5$

Substitute y=5 in equation(1), we get

$x+5=13\n\n\Rightarrow\ x=13-5=8$

Hence, the number $1 bills is 8 and the number of $5 bills is 8.

He has 6 $5 dollar bills and 3 $1 dollar bills

Solve for n. Round to the nearest tenth, if necessary.

47/n = 36/54

Answers

$(36)/(54)=(36:18)/(54:18)=(2)/(3)\n\n(47)/(n)=(2)/(3)\ \ \ |cross\ multiply\n\n2\cdot n=3\cdot47\n\n2n=141\ \ \ \ |divide\ both\ sides\ by\ 2\n\nn=(141)/(2)\n\n\boxed{n=70.5}$

$47/n = 36/54$

$47/n=2/3$

$47=2/3n$

$47=2n/3$

$47*3=2n$

$141=2n$

$141/2=n$

Decimal Form: 70.5

You are 12-15 seconds from an intersection. What should you search for in this range?

Answers

When you are 12-15 seconds away from an intersection while driving, you should search for the following:

1. Traffic lights: Look for traffic lights at the intersection and determine their current state (red, yellow, or green).

2. Hazardous situations: Scan for any potential hazards such as pedestrians, bicycles, or motorcycles approaching or crossing the intersection.

3. Vehicles: Check for any vehicles approaching the intersection, especially those that may turn or change lanes unexpectedly.

4. Road signs and markings: Pay attention to any signs or road markings that may affect your intended path or require you to take specific actions.

5. Road conditions: Observe the road conditions, looking for anything that may affect your ability to safely navigate the intersection, such as wet or icy surfaces.

By actively searching for these elements, you can anticipate potential dangers, make informed decisions, and react in a timely manner to ensure a safe passage through the intersection.

A teacher is covering a bulletin board with fabric. He has a piece of material that is 2 yards long and 36 inches wide. What size bulletin board can he cover with the material?

Answers

36'' = 1 yard
The teacher can cover a bulletin board with size 2 yards^2

Well to start our problem we need to find the information that is most important. 2 yards and 36 inches wide, and "What size bulletin board can he cover with the material?". Now that we have our information we can figure this out : 36 : 1y yard so 2y by 36in aka 2/36, so......our work can lead us too : 2 yards *squared* or 2 yards^2. Hopes I helped!

Rewrite the equation 2x + 4y + 2 = 3y + 5 in general form.