Find x if f(x) = 2x + 7 and f(x) = -1.
Answer: The required value of x is -4.
Step-by-step explanation: We are given to find the value of x if :
\(f(x)=2x+7~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)\\\\f(x)=-1~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(ii)\)
Since both the equations (i) and (ii) are the values of x, so comparing the equations, we get
\(2x+7=-1\\\\\Rightarrow 2x=-1-7\\\\\Rightarrow 2x=-8\\\\\Rightarrow x=-\dfrac{8}{2}\\\\\Rightarrow x=-4.\)
Thus, the required value of x is -4.