Factorisation.

Question 1

How is a quadratic expression formed?

Answer 1

A quadratic expression is in the form ax² + bx = c.

Question 2

What is this (x² + 7x + 6 = 0) and why is it that?

Answer 2

It is a quadratic equation because there is an “equal sign”.

Question 3

What is this (x² - 3x + 2) and why is it that?

Answer 3

It is a quadratic expression because there is no “equal” sign.

Question 4

What does FOIL stand for?

Answer 4

Firsts.
Outers.
Inners.
Lasts.

Question 5

Give the rule to the following expression:

x² + bx + c.

Answer 5

• Find the factors to the c term that ADD UP to give the b term.
• BOTH the factors have the SAME sign and they are both POSITIVE.

Question 6

Give the rule to the following expression:

x² - bx + c.

Answer 6

• Find the factors of the c term that ADD UP to give the b term.
• BOTH the factors have the same sign and they are NEGATIVE.

Question 7

Give the rule to the following expression:

x² + bx - c.

Answer 7

• Find the actors of the c term whose DIFFERENCE gives the b term.
• The factors have DIFFERENT signs and the LARGER factor is next to a POSITIVE sign and the SMALLER factor is next to the NEGATIVE sign.

Question 8

Give the rule to the following expression:

x² - bx - c.

Answer 8

• Find the factors of the c term whose DIFFERENCE gives the b term.
• The factors have DIFFERENT signs and the LARGER factor is next to a NEGATIVE sign and the SMALLER factor is next to a POSITIVE sign.

Question 9

What to practice for the test:

Answer 9

• Expanding Brackets.
• Expanding Two Brackets.
• Factorisation.
• Factorisation by Grouping.
• Factorisation Quadratics.
• A Few Factorisation Quadratics Harder.