1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
pishuonlain [190]
3 years ago
7

The area of a rectangular classroom is given by the trinomial a - 4a - 21. The length of the rectangle is a+3. What is the expre

ssion for the width of the classroom?
Mathematics
1 answer:
djverab [1.8K]3 years ago
3 0
I am assuming you wrote the problem wrong. Is it a^2?
A^2 -4A-21=0
(A-7)(A+3)=0
A=7 A=-3, ignore the negative number because it doesn't make sense if you plug in for a.
length=a+3=7+3=10
Width=7=a
You might be interested in
HELP ASAP 10 POINTS TO BRAINLIEST
Brilliant_brown [7]

Answer:

15%

Step-by-step explanation:

The cost of 2 adults and 2 children without the discount is

2 adults = 2 (55) = 110

2 children = 2 (45) = 90

Total cost = 110+90 = 200

The original price is 200 and the new price is 170

Percentage discount = (Original price - new price)/ original price * 100%

                                     = (200-170)/200 * 100%

                                     = 30/200 * 100%

                                     = .15 * 100%

                                     = 15%

6 0
3 years ago
Two buses leave a station at the same time and travel in opposite directions. One bus travels 15 /kmh faster than the other. If
Nat2105 [25]
Since the buses travel in opposite directions, the speed at which they distance themselves is the sum of their speeds.
One bus travels at speed s.
The other bus travels at speed s + 15.
The sum of the speeds is s + s + 15 = 2s + 15

speed = distance/time

distance = speed * time

366 = (2s + 15) * 2

183 = 2s + 15

168 = 2s

s = 84

The slower bus travels at 84 km/h.

s + 15 = 84 + 15 = 99

The faster bus travels at 99 km/h.

Check:
In 2 hours, the slower bus travels 2 * 84 km = 168 km
In 2 hours, the faster bus travels 2 * 99 km = 198 km
In 2 hours, the buses are 198 km + 168 km = 366 km apart.
Our answer is correct.
6 0
3 years ago
Multiply: (x – 4)(x + 5)
denpristay [2]

Answer:

D.  x2 + x - 20.

Step-by-step explanation:

(x – 4)(x + 5).

= x(x + 5) -4(x + 5).

= x2 + 5x – 4x – 20.

= x2 + x - 20.

3 0
3 years ago
PO
poizon [28]

Answer:

C=5+0.25m

Step-by-step explanation:

6 0
2 years ago
How do I solve 1/2z=9 1/4?
Nastasia [14]

Answer:

z = 9/2

Step-by-step explanation:

1/2z = 9 1/4?

z = 9/2

Explanation:

Simplify

9 x 1/4 → 9/4

Multiply 2 to both sides to cancel out the 2

1z = 9/4

Note: 1z is just z

6 0
3 years ago
Other questions:
  • How can I solve this?
    15·1 answer
  • For this question how do solve -6x-18
    15·2 answers
  • With 128, 134, 140, 146, 152, what’s the next number if the pattern continues?
    12·1 answer
  • 8+4a+6.2−9a as a simpified equtions
    9·1 answer
  • What is the straight-line distance between(6,3) and (4,-5) on a coordinate graph
    12·1 answer
  • A sample of 900 college freshmen were randomly selected for a national survey. Among the survey participants, 372 students were
    11·1 answer
  • What is the length of the missing side
    5·1 answer
  • The base of a rectangular prism has an area of 12 square centimeters. The height of the rectangular prism is 3 centimeters. What
    12·2 answers
  • The points (2, 3) and (3, 6) fall on a particular line. What is its equation in slope-intercept
    14·1 answer
  • PLEASE ANSWER ASAP IF YOU’RE GOOD AT MATH
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!