Question

Question 14.
Find the value of t if the value of 3x2 + 5x – 2t equals to 8, when x=-1.​

Answer 1

3 x 2 + 5x - 2t = 8
6 + 5x - 2t = 8
6 + (5x[-1]) - 2t = 8
6 + (-5) -2t =8
1 + 2t = 8
2t = 8-1
2t = 7
t = 7/2
t = 3.5

Answer 2

Given,

• The equation $3x^2 + 5x -2t = 8$ is given.
• Value of x = -1

To find,

• Value of t

Solution,

The value of t if the value of 3x² + 5x – 2t equals 8 when x=-1 is -5.

We can simply find the value of t by substituting the value of x = -1 in the given equation.

      p(x) = 3x² + 5x – 2t

      p(-1) = 3(-1)² +5(-1) -2t

                      3  -5 -2t = 8

                           -2 -2t = 8

                                -2t = 8+2

                                  -2t = 10

                                    t = -5

​Hence, the value of t if the value of 3x² + 5x – 2t equals 8 when x=-1 is -5.