Test: Linear equations - Year 9 MCQ

A letter multiplied by itself gives us the square of the letter

When multiplying powers, we add them together

When dividing powers we take one from the other

Don't forget a minus times a minus equals a plus but a minus times a plus equals a minus

Remember - a minus times a minus equals a plus but a minus times a plus equals a minus

Did you remember that a minus times a minus equals a plus but a minus times a plus equals a minus?

(2x + 3)(x − 5) = 2x⋅x + 2x⋅(−5) + 3⋅x + 3⋅(−5) = 2x² − 10x + 3x − 15 = 2x² − 7x − 15

'Simplifying' an expression means 'gathering together' all the 'like units'. For instance x + 2x becomes 3x; 4a - 5a becomes -a etc.

(x + 2)(x + 4) = x⋅x + x⋅4 + 2⋅x + 2⋅4 = x² + 4x + 2x + 8 = x² + 6x + 8

(3x − 2)(x + 5) = 3x⋅x + 3x⋅5 − 2⋅x − 2⋅5 = 3x² + 15x − 2x − 10 = 3x² + 13x − 10