Question

Find the value of 9u +4 given that 7u-4=3.

Simplify your answer as much as possible.
9u + 4 = 1
Х

Answer 1

`7u - 4 = 3 \\ 7u = 4 + 3 \\ 7u = 7 \\ u = (7)/(7) \\ \boxed{u = 1} \\\\f(u) = 9u + 4 \\ f(1) = 9(1) + 4 \\f(1) = 9 + 4 \\ \boxed{f(1) = 13 }`

• 13 is the right answer.

Answer 2

• first get the value of u

`7u - 4 = 3 \\ 7u = 3 + 4 \\ 7u = 7 \\{ \underline{ \: \: u = 1 \: \: }}`

• find the value of 9u + 4:

`9u + 4 = 9(1) + 4 \\ = 9 + 4 \\ { \underline{ \underline{ \: \: 13 \: \: }}}`