How can you tell when an equation in one variable has one solution?

• there is no way to tell

• one solution equations have different coefficients

• one solution equations have the same coefficient but different constants

• one solution equations have the same coefficient and constant

Tags

CCSS.8.EE.C.7A

Tags

CCSS.8.EE.C.7B

Andrea has $100 saved and earns $50 each month babysitting. Antonio has $120 saved and earns $30 a month pulling weeds. If they both save their earnings, how long will it take before Andrea and Antonio have saved the same amount of money?

Tags

CCSS.8.EE.C.8C

Which equation has infinitely many solutions?

• 2 + 3x = 5x + 3 - 2x

• 10x + 3 - 9x = 8 + x - 5

• x + 7 - 0.5x = 6.5x + 13 - 6

• 6x - 4x = 10

Tags

CCSS.8.EE.C.7A

Heather adds 2 to a number, then multiplies the sum by -3. The result is 9. Write and solve an equation to find the number, x. What is the number?

• -3(x + 2) = 9; the number is -5

• -3x + 2 = 9; the number is -7/3

• x - 6 = 9; the number is 15

• 5x = 9; the number is 9/5

Tags

CCSS.7.EE.B.4A