Steps
Result
(2x - 3)( 5x2 – 2X+7)
Use the distributive property to multiply
2x times each term in the trinomial.
10x3 - 4x2 + 14x
(result for this step only)
2 Use the distributive property to multiply
-3 times each term in the trinomial.
10x - 4x? + 14X – 15x² - 6x-
(result for step 1 and 2)
| 10² – 19x² + 144 – 6x-21
3 Use the addition property to combine
the x? terms.
4 Use the addition property to combine
the x terms
10x3 - 19x2 +8X-21
In which step did Fiona make an error?

Respuesta :

Answer:

step 2

Step-by-step explanation:

Given

(2x - 3)(5x² - 2x + 7)

2x(5x² - 2x + 7) = 10x³ - 4x² + 14x ← step 1 is correct

- 3(5x² - 2x + 7) = - 15x² + 6x - 21 ← step 2 in her working is incorrect

Adding the results from step 1 and step 2

10x³ - 4x² + 14x - 15x² + 6x - 21 ← collect like terms

= 10x³ - 19x² + 20x - 21