Simplify the expression 3(2x – 4) + x2 + 5 and then find the
numerical values for x = -2.
Answers
Step-by-step explanation:
3(2×2)+3×2+5=0
12+6+5=0
23=0
-23
★ Given:
The expression 3 x (2x – 4) + x² + 5
Numerical value of x = -2
★ To Find:
The simplification of the expression.
The answer to the expression when the value of x is -2.
★ Solution:
Simplification:
3 x (2x - 4) + x² + x
[Opening the brackets]
= 6x - 12 + x² + x
[Combining the like terms]
7x - 12 + x²
Now, giving the value of x as -2.
7 x -2 - 12 + (-2)²
= -14 -12 + 2²
=-26 + 4
= -22
Therefore the answer of the expression 3 x (2x - 4) + x² + x when the value of x = -2 is -22.
★ Verification:
We solved this question by simplifying the expression. Now we can verify the answer by giving the value of x as -2 to the expression as direct.
3 x (2x - 4) + x² + x where x = -2
= 3 x [(2 x -2) - 4) + (-2)² + (-2)
= 3 x [-4 - 4] + 2² + (-2)
= 3 x -8 + 4 - 2
= -24 + 2
= -22
We got the same answer.
Hence, verified!