diketahui fungsi f:R -> R dan g:R->R dirumuskan dengan f(X)= 2X + 3 dan g(x)= 7X - 1 , maka (go F) (.... Question from @rahmaoktaviani589

May 2022 1 8 Report

diketahui fungsi f:R -> R dan g:R->R dirumuskan dengan f(X)= 2X + 3 dan g(x)= 7X - 1 , maka (go F) (-4)=....
A.36
B.18
C.9
D.- 18
E.- 36

Gusti2601

$\mathbb \color{aqua} \underbrace{JAWABAN}$

E. -36

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$\mathbb \color{orange} \underbrace{PENYELESAIAN}$

$\underline{ \overline{ \boxed{ \bold{diketahui}}}}$

f(x) = 2x + 3
g(x) = 7x - 1

$\\ \underline{ \overline{ \boxed{ \bold{ditanya}}}}$

(g o f)(-4)

$\\ \underline{ \overline{ \boxed{ \bold{jawab}}}}$

$\begin{aligned} \sf (g \circ f)(x) & = \sf g(f(x)) \\ \sf (g \circ f)(x) & = \sf g(2x + 3) \\ \sf (g \circ f)(x) & = \sf 7(2x + 3) - 1 \\ \sf (g \circ f)(x) & = \sf 14x + 21 - 1 \\ \sf (g \circ f)(x) & = \sf 14x + 20 \\ \sf (g \circ f)( - 4) & = \sf 14( - 4) + 20 \\ \sf (g \circ f)( - 4) & = \sf - 56 + 20 \\ \sf (g \circ f)( - 4) & = \bold{ - 36} \end{aligned}$

$\\ \\ \huge \color{lightgreen} \xrightarrow \textsf{\textbf{cara lain : }} \\ \\$

$\begin{aligned} \sf (g \circ f)( - 4) & = \sf g(f( - 4)) \\ \sf (g \circ f)( - 4) & = \sf g(2( - 4) + 3) \\ \sf (g \circ f)( - 4) & = \sf g( - 8 + 3) \\ \sf (g \circ f)( - 4) & = \sf g( - 5) \\ \sf (g \circ f)( - 4) & = \sf 7( - 5) - 1 \\ \sf (g \circ f)( - 4) & = \sf - 35 - 1 \\ \sf (g \circ f)( - 4) & = \bold{ - 36 }\end{aligned}$

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$\mathbb \color{red} \underbrace{KESIMPULAN}$

Jadi, nilai (g o f)(-4) adalah -36

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