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
hodyreva [135]
4 years ago
7

Solve 2a + 21 = 8a - 9, step by step

Mathematics
1 answer:
Rom4ik [11]4 years ago
6 0
2a + 21 = 8a - 9

Combine like terms. 

2a + 21 = 8a - 9
-2a          -2a

21 = 6a - 9 
+9          +9

30 = 6a
6a/6 = 30/6
a = 5

Answer: a = 5
You might be interested in
Drew has more than 4 times as many baseball cards as mark. Katie has fewer than half as many cards as mark. Mark has m baseball
Sphinxa [80]

Answer:

Cards with Mark = 30

Cards with Drew  = 120

Cards with Katie = 12

Step-by-step explanation:

The complete question is

Drew has 4 times as many baseball cards as Mark. Katie has 3 fewer than than half as many cards  as Mark. In all they have 162 baseball cards. How many does each have?

Solution -

Let the number of cards with Mark be "X"

Number of cards with Drew = 4 *X = 4X

Number of Cards with Katies = 0.5 X -3

Sum of all the cards is equal to 162

X+4X + 0.5 X -3 = 162

5.5 X = 165

X = 30

Cards with Mark = 30

Cards with Drew = 4 * 30 = 120

Cards with Katei = 15-3 = 12

5 0
3 years ago
Write the equation of the line that passes through the points (−7,0) and (6,−4).
Over [174]

Answer:

y=-4/13x-28/13

Step-by-step explanation:

m=y2-y1/x2-x1

m=-4-0/6-(-7)

m=-4-0/6+7

m=-4/13

y-y1=m(x-x1)

y-0=-4/13(x-(-7))

y-0=-4/13x-28/13

y=-4/13x-28/13

5 0
3 years ago
Help me ASAP plz!!!!
elena55 [62]
(2, -1), (6,- 4), and (6, -1). Hope this helps man!
6 0
3 years ago
Read 2 more answers
Use the Distributive Property to solve the equation.
Arada [10]

Answer:

x= - 9

Step-by-step explanation:

  1. - 8(x +7) = 16
  2. -8x - 56 = 16
  3. -8x = 16 + 56
  4. -8x = 72
  5. x = 72 ÷ (-8)
  6. x = -9
5 0
3 years ago
In a certain clothing store, 4 shirts and 6 ties cost $70, and 2 shirts and 4 ties cost $42. What is the cost of each tie?
Oksanka [162]

Answer:

  $7

Step-by-step explanation:

Your two equations are ...

  • 4s +6t = 70
  • 2s +4t = 42

Double the second equation and subtract the first:

  2(2s +4t) -(4s +6t) = 2(42) -(70)

  2t = 14 . . . . . simplify

  t = 7 . . . . . . . divide by 2

The cost of each tie is $7.

3 0
4 years ago
Other questions:
  • A compact-disc case, or jewel case is 14 cm long, 12.5 cm wide, and 1 cm tall. What is the volume of the jewel case?
    15·1 answer
  • Expand the expression: -5(4-7c)​
    12·2 answers
  • 9) Order the fractions from least to greatest. 2 4 , 4 5 , 7 10 , 2 3 A) 2 4 , 7 10 , 2 3 , 4 5 B) 7 10 , 2 4 , 2 3 , 4 5 C) 2 4
    6·1 answer
  • Each student in a pottery class is responsible for cleaning the area around his or her workspace at the end of the lesson. Each
    10·1 answer
  • Find the perimeter of the triangle
    11·1 answer
  • 2 5 7 Which algebraic expression represents the phrase "two times the quantity of a number minus 12"? 0 2y - 12 0 207-12) O 200
    11·1 answer
  • Which of the equations below represents a line parallel to the x-axis?
    12·1 answer
  • Robin will choose a movie from the Red Box when all movies are in stock. If she
    14·1 answer
  • The wall around Lemon's house is 4233 centimeters long. The wall around Hercules' house is 65,581 millimeters long. What is the
    6·1 answer
  • Solve for the unknown in the following diagram. Round the answer to two decimal places.<br>cm​
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!