Khan Academy Algebra

Which of the following is a logical reason we use letters in algebra?

• We wanted to make math harder.

• There were enough numerals, so we had to start borrowing letters.

• Someone got confused and thought zero looked like an O and started using letters.

• We needed symbols to represent unknown numbers.

Tags

CCSS.6.EE.B.6

The word Algebra comes from an Arabic word roughly translated as _________________.

• balancing

• restoration/completion

• solving

• mathematics

Tags

CCSS.L.5.4B

CCSS.L.6.1E

_____________ are used to represent unknown numbers.

Tags

CCSS.6.EE.B.6

Greek mathematician Diophantus is sometimes credited as the father of algebra. Who did the video say is arguably really the father of Algebra?

• Pythagoras

• Euclid

• al-Kwarizmi

• Aristotle

Tags

CCSS.8.EE.C.7B

Solve: -2(2x - 8) + 8x = 12

• x = 1

• x = -1

• x = 4

• x = -4

Tags

CCSS.8.EE.C.7B

What is the first step to solve this equation?

-2(x - 3) + 5x = 72

• Combine Like Terms

• Distribute

• Change the variables with the constants

• Throw it away and go to Starbucks

Tags

CCSS.8.EE.C.7B

Solve: 2(x + 2) = -8

• x = -4

• x = 1,234,567

• x = 6

• x = -6

Tags

CCSS.7.EE.B.4A

What is the second step needed to solve this equation:

4(x - 5) - 3x + 4 = 250

• Solve for x

• Add all the constants with the coefficients

• Combine Like Terms

• Distribute

Tags

CCSS.8.EE.C.7B

Solve the following equation:

25 = -5(x - 2)

• x = -3

• x = 3

• x = 5

• x = -5

Tags

CCSS.7.EE.B.4A

Solve: 91 = 7(x + 8)

• x = -5

• x = 90

• x = 5

• x = 1

Tags

CCSS.7.EE.B.4A