Answer:
a= 25/3
b= 19/3
Step-by-step explanation:
step by step expl. in pic
Answer:
a = 5, b = - 13
Step-by-step explanation:
The Remainder theorem states that the remainder when f(x) is divided by (x - a) is equal to f(a)
Thus the remainder for division by (x + 2) is zero , then by substituting x = - 2 into the expression.
2(- 2)³ + a(- 2)² + b(- 2) - 30 = 0
2(- 8) + 4a - 2b - 30 = 0
- 16 + 4a - 2b - 30 = 0
- 46 + 4a - 2b = 0 ( add 46 to both sides )
4a - 2b = 46 → (1)
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Similarly when f(x) is divided by (cx - a) the remainder is f([tex]\frac{c}{a}[/tex] )
The remainder on dividing by (2x - 1) is - 35, then by substituting x = [tex]\frac{1}{2}[/tex]
2([tex]\frac{1}{2}[/tex] )³ + a([tex]\frac{1}{2}[/tex] )² + [tex]\frac{1}{2}[/tex] b - 30 = - 35
2([tex]\frac{1}{8}[/tex] ) + [tex]\frac{1}{4}[/tex] a + [tex]\frac{1}{2}[/tex] b - 30 = - 35 ( add 30 to both sides )
[tex]\frac{1}{4}[/tex] + [tex]\frac{1}{4}[/tex] a + [tex]\frac{1}{2}[/tex] b = - 5 ( multiply through by 4 to clear the fractions )
1 + a + 2b = - 20 ( subtract 1 from both sides )
a + 2b = - 21 → (2)
Solve (1) and (2) simultaneously )
Add (1) and (2) term by term to eliminate b
5a = 25 ( divide both sides by 5 )
a = 5
Substitute a = 5 into (2)
5 + 2b = - 21 ( subtract 5 from both sides )
2b = - 26 ( divide both sides by 2 )
b = - 13
