Question

if f(x) = ax3 - bx + 6 and f(2) = 3 and f(4) = 30 find a and b.​

Answer 1

Step-by-step explanation:

F(2)=3

4a-2b+6=3

4a-2b+3=0(1)

f(4)=30

16a-4b=24(2)

After solve both equations

a=15/4

b=9

Answer 2

$\huge\underline\mathcal\red{♡ĂnSwer♡}$

f(2)=(2)^3a-2b+6

3=8a-2b+6

8a-2b= -3 ......eq1

f(4)=(4)^3a-4b+6

30-6=64a-4b

24=64a-4b

24=4(16a-b)

6=16a-b...........eq2

Now multiply 2 in eq2 and subtract both eq

(16a-b)-(16a-4b)=6+4

3b=10

b=10/3

Now put b in eq2

6=16a-10/3

6+10/3=16a

(18+10)/3×16=a

a=7/12