Answer:
f(x) = 2x³ - 5x² + 7x - 7
Explanation:
In the division statement: m ÷ n = q +
Let us use the fact above to solve the question
∵ f(x) is divided by (2x - 3), the quotient is x² - x + 2 and the remainder is -1
∴ f(x) is the dividend ⇒ m
∴ (2x - 3) is the divisor ⇒ n
∴ (x² - x + 2) is the quotient ⇒ q
∴ -1 is the remainder ⇒ r
→ Use the rule above to find f(x)
∵ f(x) = (x² - x + 2) × (2x - 3) + -1
∴ f(x) = (x² - x + 2)(2x - 3) - 1
→ Multiply the 2 brackets at first
∵ (x² - x + 2)(2x - 3) = x²(2x) + x²(-3) + -x(2x) + -x(-3) + 2(2x) + 2(-3)
∴ (x² - x + 2)(2x - 3) = 2x³ - 3x² - 2x² + 3x + 4x - 6
→ Add the like terms
∴ (x² - x + 2)(2x - 3) = 2x³ + (-3x² - 2x²) + (3x + 4x) - 6
∴ (x² - x + 2)(2x - 3) = 2x³ + (-5x²) + 7x - 6
∴ (x² - x + 2)(2x - 3) = 2x³ - 5x² + 7x - 6
→ Substitute it in f(x)
∴ f(x) = 2x³ - 5x² + 7x - 6 - 1
→ Add the like term
∵ f(x) = 2x³ - 5x² + 7x + (- 6 - 1)
∴ f(x) = 2x³ - 5x² + 7x + (-7)
∴ f(x) = 2x³ - 5x² + 7x - 7