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19 votes
19 votes
A function is shown below.
f(x) = 8x - 11

What value of x makes f(x) = 21?

User Bharat Dodeja
by
2.9k points

2 Answers

18 votes
18 votes
f(x)=8x-11
f(21)
x=21
f(21)=8(21)-11
f(21)=168-11
f(21)=157
User Steely
by
2.5k points
11 votes
11 votes

The correct value in this function is f(21) = 157

This question is related to substitution of values. To solve it, just: change x by the indicated value and thus calculate normally.

– The given function being f(x) = 8x - 11, replace X by 21:

f(x) = 8x - 11

f(21) = 8 . 21 - 11

– Finally, just calculate the expression now, like this, multiplying and subtracting the numbers:

f(21) = 8 . 21 - 11

f(21) = 168 - 11

f(21) = 157

Therefore, the correct value of this function will be f(21) = 157

User Pierre Besson
by
2.8k points