Advertisements
Advertisements
Question
If x = − 3, find the value of 2x3 + 8x2 – 15.
Advertisements
Solution
x = − 3
∴ 2x3 + 8x2 – 15
= 2 (– 3)3 + 8 (– 3)2 – 15
= 2 (– 27) + 8 (9) – 15
= – 54 + 72 – 15
= – 54 – 15 + 72
= – 69 + 72
= 3
APPEARS IN
RELATED QUESTIONS
Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.
xz + cd = ...................
Find the value of 3a − 2b, when a = 8 and b = 10
If x = 2, y = 5 and z = 4, find the value of the following:
zx
If x = 2, y = 5 and z = 4, find the value of the following:
`("x"^2"y"^2"z"^2)/"xz"`
If a = 3, find the values of a2 and 2a.
If m = 2, find the difference between the values of 4m3 and 3m4.
Evaluate:
35b – (16b + 9b)
Simplify:
`3"x"+(2"x"-overline("x"+2))`
Insert the bracket as indicated:
m2 + x2 − p2 = − (...................)
If x = a2 – bc, y = b2 – ca, and z = c2 – ab; find the value of ax + by + cz
