Question

Consider the following algebraic expression. 3xb +4x²+2 The value of this algebraic expression when x = 2 is 3. Find b

A. -2.5
B. -1
C. 3.5
D. 3​

Answer 1

`b = -2.5`

Explanation:

`~~~~~~3xb+4x^2 +2 = 3\\\\\implies 3* 2b +4 * 2^2 +2 = 3~~~~~~~~~~~~~~~~~~;x=2\\\\\implies 6b+16+2 = 3\\\\\implies 6b +18 =3\\\\\implies 6b = 3-18\\\\\implies 6b = -15\\\\\implies b = -\frac{15}6\\\\\implies b = - \frac 52\\\\\implies b = -2.5`