Question

please solve this problem. fast

Answer 1

let p(x)=2x³+ax²-bx-15,

since 2x+3 is a factor, then

p(-3/2) =0,

2×(-3/2)³ + a×(-3/2)² - b×(-3/2) -15 =0,

2 × -27/8 + a×9/4 +3b/2 - 15=0,

-27/4 + 9a/4 + 3b/2 - 15=0,

(-27+9a+6b-60)/4 =0,

then

9a+6b-87=0,

3a+2b-29=0,

3a+2b=29 ...............eq(1),

now according to the question

p(1)=-5,

2(-1)³+a(-1)²-b(-1)-15=-5,

-2+a+b-15=-5,

then

a+b=-5+15+2,

a+b=12 ............eq(2),

now just solve these two easy equations so that you will get the correct answer.........

since
a+b=12,
then
a+b=12 × 2,
2a+2b=24,

now solve

3a+2b=29 -----eq(1),
2a+2b=24 ------------eq(2),

subtract eq(2) from eq(1), we get

(3a+2b) - (2a+2b) =29-24,

3a+2b-2a-2b=5,

a=5,

put this value of a in eq(2), we have

a+b=12,

5+b=12,

b=12-5,

b=7

a=5,

b=7

Answer 2

Answer:

7 and 5 is answer dear friend