Writing Equations in Two Variables

What is the value of s in the equation 3r - 5s = 10 when r = 10

• 4

• 8

• 100

• 200

The soccer team collected $1600 at a car wash fundraiser. They charged $10.00 for small vehicles and $20.00 for larger vehicles. The amount collected can be modeled by the equation 10x + 20y = 1600 , where x represents the number of small vehicles and y represents the number of larger vehicles. If the number of larger vehicles washed was 50, how many small vehicles were washed in total?

• 55

• 60

• 130

• 150

Samil sells iced tea for $1.49 per bottle and water for $1.25 per bottle. She wrote an equation to find the number of bottles she needs to sell to earn $100.

1.25x + 1.49 = 100

What error did Samil make in writing the equation?

• Samil's equation did not use the correct total for sales.

• Samil’s equation did not use the correct price for the bottles of iced tea.

• Samil's equation did not consider the number of bottles of water.

• Samil's equation did not consider the number of bottles of iced tea.

Tags

CCSS.HSA.CED.A.3

What is the value of x in the equation 7x + 2y = 48, when y = 3?

• 6

• 7

• 8

• 9

Tomas is making trail mix using granola and walnuts. He can spend a total of $12 on the ingredients. He buys 3 pounds of granola that costs $2.00 per pound. The walnuts cost $6 per pound. He uses the equation to represent the total cost, where x represents the number of pounds of granola and y represents the number of pounds of walnuts. He solves the equation for y, the number of pounds of walnuts he can buy.

2x + 6y = 12

2(3) + 6y = 12

6 + 6y + 6 = 12 + 6

6y = 18

y = 3

Which is the first error that Tomas made?

• Tomas substituted the 3 for x when he should have substituted 6 for x.

• Tomas added 6 to both sides of the equation instead of subtracting 6.

• Tomas should have written the equation as .

• Tomas substituted 3 for x when he should have substituted 3 for y.

Tags

CCSS.HSA.REI.A.1

What is the value of x in the equation  $3x\ -\ \frac{1}{9}y\ =\ 18$ , when y = 27?

• 5

• 7

• 45

• 63