Question

An expression is shown.

(3.x2 + 2x – 5) - (5x2 - 4x + 1)
O a
8x2 + 6x 6
Ob
- 2x2 + 62 - 6
ос
- 2x2 - 2.3 – 4
od
8x2
2x – 4

Answer 1

The expression needs to be simplified to get the final answer.

Hint:

- x - = +

- x + = -

+ x - = -

+ x + = +

A negative number multiplied by a negative number gives a positive number.

A negative number multiplied by a positive number gives a negative number.

A positive number multiplied by a negative number gives a negative number.

A positive number multiplied by a positive number gives a positive number.

`\begin{gathered} (3x^2+2x-5)-(5x^2-4x+1) \\ U\sin g\text{ the negative sign outside the bracket to expand the bracket by multiplying through,} \\ 3x^2+2x-5-5x^2+4x-1 \\ \text{Collecting the like terms,} \\ 3x^2-5x^2+2x+4x-5-1 \\ -2x^2+6x-6 \end{gathered}`

Therefore, the simplified expression is

`-2x^2+6x-6`

The correct answer is option B.