Home
Class 6
MATHS
If x = -2, find the value of 3x^(3)– 5x^...

If x = -2, find the value of `3x^(3)– 5x^(2) +4`.

Text Solution

AI Generated Solution

The correct Answer is:
To find the value of the expression \(3x^3 - 5x^2 + 4\) when \(x = -2\), we will follow these steps: ### Step 1: Substitute the value of \(x\) We start by substituting \(x = -2\) into the expression: \[ 3(-2)^3 - 5(-2)^2 + 4 \] ### Step 2: Calculate \((-2)^3\) Next, we calculate \((-2)^3\): \[ (-2)^3 = -2 \times -2 \times -2 = -8 \] So, we can rewrite the expression as: \[ 3(-8) - 5(-2)^2 + 4 \] ### Step 3: Calculate \((-2)^2\) Now, we calculate \((-2)^2\): \[ (-2)^2 = -2 \times -2 = 4 \] Now, substitute this back into the expression: \[ 3(-8) - 5(4) + 4 \] ### Step 4: Multiply the coefficients Now we multiply the coefficients: \[ 3 \times -8 = -24 \] \[ -5 \times 4 = -20 \] So, the expression now looks like: \[ -24 - 20 + 4 \] ### Step 5: Combine the terms Now, we combine the terms: \[ -24 - 20 = -44 \] Then add 4: \[ -44 + 4 = -40 \] ### Final Answer Thus, the value of the expression \(3x^3 - 5x^2 + 4\) when \(x = -2\) is: \[ \boxed{-40} \] ---
Promotional Banner

Similar Questions

Explore conceptually related problems

If x=5, find the value of : 3x^(2)-8x-10

If x=5, find the value of : 2x^(3)-4x^(2)-6x+25

If 5^(x +1) = 25^(x-2) , find the value of 3^(x-3) xx 2^(3-x) .

Find the value of : 4x^(3)-5x^(2)-6x+7 when x=3

If x= -5 + sqrt(-16) , find the value of x^(4) + 9x^(3) + 35x^(2)-x + 4

If x= -2 - sqrt3i , where i= sqrt(-1 , find the value of 2x^(4) + 5x^(3) + 7x^(2)-x+ 41

Find the value of 3x^2-5x+8 for x=3

If x=2 and y=5 find the values of : (3x)/(2y)

If x : y = 4 : 7 , find the value of (3x + 2y) : (5x + y) .

If x = 2 and y = 1, Find the value of (-4x^(2)y^(3)) xx (-5x^(2)y^(5)) .