Solving for X

Equations

Isolate the variable by using inverse operations.

Isolate = by itself

Variable = letter representing an unknown number

Inverse Operations = opposite (add/subtract or multiply/divide)

One Step Equations

Undo the operation to solve for your variable.

Multiple Choice

Solve for b.

9b=18

• 9

• 2

• 27

• -11

Multiple Choice

Solve for x.

x + 17 = 4

• 21

• -13

• 68

• $$\frac{4}{17}$$

Two Step Equations

Undo the operations while following reverse of PEMDAS.

Multiple Choice

Solve for n.

-6n + 6 = 60

• -20

• 18

• -9

• -16

Multiple Choice

Solve for x.

$$\frac{x}{5}-10=-10$$  

• 0

• 18

• -25

• 1

Multiple Choice

Solve for r.

$$-6r-9=111$$  

• -6

• -17

• 11

• -20

Multiple Choice

Solve for x.

$$8\left(1+x\right)=-8$$  

• 10

• 7

• -2

• 17

Multiple Choice

$$\frac{3}{2}x\ =6$$  solve for x

• 4

• 3

• 12

• 2

Multiple Choice

3x+1=7

• 2

• $$\frac{8}{3}$$

• 3

• 8

Multiple Choice

27 = 9a

• a=3

• a=36

• a=18

• a=9

Multiple Choice

Solve for y:

-2y - 7 = 3

• 5

• -5

• 6

• -6

Multiple Choice

Solve:

-3y - 5 = 10

• 6

• 7

• -5

• 21

Multiple Choice

Evaluate 2a + 4b 
if a = 10     and    b = 6

• 20

• 24

• 44

• 4

Multiple Choice

3x + 8   if x = 2

• 13

• 14

• 15

• 16

Multiple Choice

Evaluate 8a - b     if a = 10   and   b = 6

• 74

• 38

• 1000

• 9000

Multiple Choice

Identify the coefficient:

$$3x^2$$  

• 3

• x

• 2

Multiple Choice

Identify the constant in this expression:

$$3x^2+4y-2xy+7$$  

• 3

• 4

• 2

• 7

Multiple Choice

What is the 4 in this expression?

$$4x-12$$  

• coefficient

• constant

• variable

Multiple Choice

What is the x in this expression?

$$4x-12$$  

• coefficient

• constant

• variable

Multiple Choice

What are the variable(s) in this expression?

$$a+3b$$  

• a

• b

• a and b

Multiple Choice

Which of the following is equivalent to  $$12xy\ -3\ +4xy\ -xy\ +5$$  

• $$15xy+2$$  

• $$16xy+8$$  

• $$17x^2y$$  

• $$17xy+8$$  

Multiple Choice

Which of the following is equivalent to the expression 3(x+7)

• 3x+7

• 3x+10

• 3x+21

• 3x+4

Multiple Choice

What is 0.00000786 in scientific notation?

• $$7.86\ x\ 10^{-5}$$  

• $$7.86\ x\ 10^5$$  

• $$7.86\ x\ 10^{-6}$$  

• $$7.86\ x\ 10^6$$  

Multiple Choice

What is 47,500,000 in scientific notation?

• $$47.5\ x\ 10^6$$  

• $$4.75\ x\ 10^7$$  

• $$4.75^7$$  

• $$475\ x10^5$$  

Multiple Choice

What is $$7.8\ x\ 10^9$$  in standard form?

• 7,800,000,000,000

• 78,000,000,000

• 7,800,000,000

• 0.0000000078

Multiple Choice

Write 0.0000000674 in scientific notation.

• $$6.74\ x\ 10^{-7}$$  

• $$6.74\ x\ 10^7$$  

•   $$0.674\ x\ 10^{-7}$$  

• $$6.74\ x\ 10^{-8}$$  

Multiple Choice

Jo is thinking of a number. Four less than 9 times the number is 176. How could I find Jo's number?

• 9x - 4 = 176
• 4 - 9x = 176
• 9x + 4 = 176
• 4x + 9 = 176

Multiple Choice

Oshgosh would like to buy a new pair of skates for $115. So far he has saved $40. If he earns $7.50 per hour, how could I find out how many hours he must work in order to buy the skates?

• 40 + 7.50x = 115
• 40x + 7.50 = 115
• 40 + 7.50 = 115
• 40 + 17.50x = 115

Multiple Choice

Three desks and a bookcase together weigh 157 pounds. The bookcase weighs 34 pounds. Which equation could help me find out how much each desk weighs?

• 34 + 3 = 157
• 34x + 3 = 157
• 3x + 34 = 157
• x + 34 = 157

Multiple Choice

Grandpa Gump is 63 years old. His age is 2 years less than 5 times the age of Billy Gump. How could I find out how old Billy is?

• x/5 - 2 = 63
• 5x - 2 = 63
• 2x - 5 = 63
• 5x + 2 = 63

Multiple Choice

Which expression shows "the sum of 5 and x"

• 5 - x

• 5 + x

• 5x

• 5/x

Multiple Choice

Perry has 17 fewer baseball cards than Pete.
If b represents the number of cards Pete has, write an expression for how many baseball cards Perry has.

• b + 17
• b -17
• 17 - b
• 17 + b

Multiple Choice

Write the expression.
Twelve fewer questions than were on the first test. 

• 12 + q
• q - 12
• q x 12
• q ÷ 12

Multiple Choice

Rebecca paid $324 for concert tickets. Rebecca bought "x" amount of tickets.

Choose the expression that shows how much each ticket cost.

• $$324+x$$

• $$324-x$$

• $$324\times x$$

• $$324\div x$$

Multiple Choice

-18 +(-6)

• 3
• -3
• -12
• -24

Multiple Choice

(-4)(-5)

• -9
• -20
• 9
• 20

Multiple Choice

-32/8

• -4
• -5
• 4
• 24

Multiple Choice

-2 + (-5)

• -3
• 3
• -7
• 7

Multiple Choice

35 - (-35) 

• 0
• -70
• 70
• 1