Expressions and Equations
What is a variable?
A variable is a letter that represents a number.
Solve x+7=19.
x = 12
Write 5×5×5 using exponents.
53
Use the distributive property to rewrite 4(6+3)
4(6+3) = 24 + 12
A car travels 180 miles in 3 hours. What is the unit rate?
60 miles per hour.
Write an expression for “5 more than a number.”
5 + x OR x + 5
Solve 8x=64.
x = 8
Solve 24
2 x 2 x 2 x 2 = 16
Simplify 6(2x−5) using the distributive property.
12x - 30
John had x video game tokens. After spending 12, he had 28 left. Write an equation to represent the situation then solve.
x - 12 = 28
x = 40
Write an expression that represents “twice a number minus 9.”
2x - 9
Solve 5x−3=22.
x = 5
Which is larger: 25 or 52? Explain
25 is larger because it equals 2 x 2 x 2 x 2 x2 =32 and 52 is 5 x 5 or 25.
Write an expression equivalent to 7x - 21 using the distributive property.
7(x - 3)
A rectangle’s length is x and width is 4. Its perimeter is 26. Write an equation to represent the situation.
x + x + 4 + 4 = 26
2x + 8 = 26
Solve 3x+4 when x=6.
22
Solve 2x+9=25.
x = 8
Solve 62 - 10.
36 - 10 = 26
Solve for x: 3(x + 2) = 15
3(x + 2) = 15
3x + 6 = 15
3x = 9
x = 3
Write a word problem that is represented by the equation 2x+8=24
Answers will vary.
Is x=0 a solution to 7x+2=2? Why or why not?
Yes because when you plug in x=0 then we get 7 x 0 + 2 = 2 which equals 0 + 2 = 2 and that is correct.
Solve 4(x−1)=20
x = 6
Write a numerical expression with an exponent that equals 81.
92 or 34
Solve for x: 5(x-3) = 60
5(x - 3) = 60
5x - 15 = 60
5x = 75
x = 15
A plant grew x inches each week. After 3 weeks it grew 18 inches. Write and solve an equation to solve how many inches it grew each week.
3x = 18
x = 6