Writing Equations

What is the variable in this expression? 3x=21

• 3

• x

• 21

What equation is represented in this tape diagram?

• x+3=9

• 9x=3

• 3x=9

• 9+3=x

What is the value of x in this tape diagram?

• 3x

• 9

• 3

• 1/3

What is the value of x in this tape diagram?

• 7

• 5

• 35

• 5x

A cell phone company charges $3.00 to make a phone call plus $0.15 for each minute for each minute you talk. Which equation would you use to determine the total cost, c, of a phone call that is m number of minutes long?

• c = 3.00 - 0.15m

• c = 0.15 + 3.00m

• 3.00 = c + 0.15

• c = 3.00 + 0.15m

Samuel bought 3 tires for $79.95 each and some rims for $59 each. He spent a total of $534.85. Which equation could be used to find the number of rims, r, Samuel bought?

• 3(79.95) - 59r = 534.85

• 79.95r - 59(3) = 534.85

• 3(79.95) + 59r = 534.85

• 79.95r + 59(3) = 534.85

Julie bought 5 pairs of shoes and 4 blouses. The shoes were priced at $19 per pair and the blouses cost $16.50 each. Which equation can be used to find the total cost, t, she spent on the shoes and blouses?

• 5(16.50) + 4(19) = t

• 5(16.50) - 4(19) = t

• 4(16.50) + 5(19) = t

• 4(16.50) - 5(19) = t

What is the first step to solve this equation 2x + 11 = 23?

• Add 3 to both sides

• Subtract 11 from both sides

• Add 1 to both sides

• Divide 3 on both sides

Which equation matches the following situation? 331 students went on a field trip. Six buses were filled and 7 students traveled in cars. How many students were in each bus?

• n= # of students in each bus; 6n + 7 =331

• n=# of buses; 6n + 7 =331

• n= # of students in each bus; 6 + 7n =331

• n= # of students in each bus; 6n - 7 =331

WRITE AN EQUATION
April had $24 to spend on seven pencils. After buying them she had $10. How much did each pencil cost?

• n=total cost pencils; 7n+10=24

• n=cost of 1 pencil; 7n-10=24

• n=cost of 1 pencil; 7n+10=24

• n=cost of 1 pencil; -7n-10=24