Class 9th math 3.3 solution english PCTB

Question 6: Consider the function defined by \(f(x)=5x+1\). If \(\small{f(x)=32}\), find the \(x\) value.

Solution:

\(f(x)=5x+1\)

\(5x+1=32\)\(\quad \because f(x)=32\)

\(5x=32-1\)

\(5x=31\)

\(x=\large{\frac{31}{5}}\)

To match the answer given in the book, we should use \(f(x)=5x+2\) instead of \(f(x)=5x+1\).

\(f(x)=5x+2\)

\(5x+2=32\)\(\quad \because f(x)=32\)

\(5x=32-2\)

\(5x=30\)

\(x=\large{\frac{30}{5}}\)

\(x=6\)

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