Question

if 3x²+ax+4 is perfectly divisible by x-5 ,then the value of a is

Answer 1

If it is perfectly divisible, the remainder would be 0

Since x - 5 is a factor, it's zero will be 5

that is, x = 5

By remainder theorem,

p(x) = 3x² + ax + 4 = 0 at p(5)

at p(5) = 3(5)² + 5a + 4 = 0

=> 3 × 25 + 5a + 4 = 0

=> 75 + 5a + 4 = 0

=> 5a + 79 = 0

=>5a = (-79)

=> a = (-79)/5


Your answer, a = -79/5


Hope it helps dear friend ☺️✌️

Answer 2

here is the solution,

if 3x²+ax+4 is divisible by x-5 then p(5)=0

p(5)= 3(5)²+a(5)+4=0

75+5a+4=0

79 + 5a = 0

5a = -79

a = -79/5