More examples of factoring by grouping | Algebra I | Khan Academy

When factoring a quadratic expression like 4x^2 + 25x - 21 using the grouping method, what is the first step to find two numbers, A and B?

• A * B must equal 25, and A + B must equal -21.

• A * B must equal (4 * -21), and A + B must equal 25.

• A * B must equal 4, and A + B must equal 25.

• A * B must equal -21, and A + B must equal 4.

For the quadratic expression 4x^2 + 25x - 21, what two numbers (A and B) satisfy the conditions A * B = -84 and A + B = 25?

• -4 and 21

• 4 and -21

• -3 and 28

• 3 and -28

After finding the numbers -3 and 28 for the expression 4x^2 + 25x - 21, how should the middle term, 25x, be rewritten to proceed with factoring by grouping?

• 4x - 21x

• 28x - 3x

• 25x + 0x

• 4x + 21x

What is the completely factored form of the quadratic expression 4x^2 + 25x - 21?

• (x + 7)(4x - 3)

• (x - 7)(4x + 3)

• (4x + 7)(x - 3)

• (4x - 7)(x + 3)

When factoring the expression 6x^2 + 7x + 1, what two numbers multiply to 6 and add up to 7?

• 2 and 3

• 1 and 6

• 7 and 1

• 6 and 0

To factor the expression 6x^2 + 7x + 1 by grouping, the term 7x is split into which two terms?

• 3x + 4x

• 5x + 2x

• 6x + 1x

• 7x + 0x

What is the completely factored form of the expression 6x^2 + 7x + 1?

• (x+1)(6x+1)

• (6x+1)(x-1)

• (x+6)(x+1)

• (6x-1)(x+1)

What is the first step to factor the expression -x^3 + 17x^2 - 70x?

• Factor out x^2

• Factor out -x

• Factor out 17x

• Factor out -70