Linear Equations to Solve Problems

On Monday Joe bought 10 cups of coffee and 5 doughnuts for his office at the cost of $16.50. On Tuesday he bought 5 cups of coffee and 10 doughnuts for a total of $14.25. Which equations could be used to determine the cost of the coffee?

• 10c + 5d = 14.25
  5c + 10d = 16.50

• 10c + 5d = 16.50
  5c + 10d = 14.25

• c + d = 10
  5c + 10d = 16.50

• c + d = 5
  5c + 10d = 16.50

What is the solution to this system of linear equations? 
Use substitution.

y = -2x - 6
-2x + y = 6

• (0, -3)

• (-3, -12)

• (-3, 0)

• (3, -12)

What is the value of x in the solutiont o this system of linear equations?
Use substitution.

y = -3x + 3
- 2x + 2y  = 6

• 0

• No solution

• 4

• - 4

Solve by elimination:
3x+7y=23

-3x-7y=-17

• No solution

• ARN

• (-3,3)

• (3,3)

Solve by elimination:
7x + y = -9
-3x - y = 5

• No solution

• (1,8)

• (-2,-3)

• (-1,-2)

4x +  8y = 20
-4x + 2y = -30
Which variable will be eliminated?

• The  x

• The  y

• The  z

• The unknown

-6x + 5y = 1
 6x +  4y = -10

• (1,-1)

• (0,-1)

• (1,1)

• (-1,-1)

Based on the question below, what equation format is it written in?

Kate bought $23.40 worth of two types of bird seed. Thistle bird seed sells for $1.60 per pound and Wild bird seed sells for $0.95 per pound. If she bought 12 pounds of wild bird seed, write and solve a linear equation to find the amount of Thistle bird seed she purchased.

• Standard Form

• Point Slope

• Two-Points

• Slope-Intercept

Based on the question below, what equation format is it written in?

Jeff is keeping track of his weight over several weeks. After 2 weeks, he weighs 194 pounds. After 6 weeks, he weighs 186 pounds. Write and solve a linear equation to find Jeff's weight after 12 weeks.

• Standard Form

• Point Slope

• Two-Points

• Slope-Intercept

Based on the question below, what equation format is it written in?

A landscape supply business charges $35 to deliver mulch. The cost of the mulch is $29 per cubic yard. Write and solve a linear equation to find the cost of having 6 cubic yards of mulch delivered to a site.

• Standard Form

• Point Slope

• Two-Points

• Slope-Intercept