What will the first step look like for the substitution problem:

[tex]\[
\begin{array}{l}
y = 2x \\
x + y = 9
\end{array}
\][/tex]

A. [tex]\( 2x + y = 9 \)[/tex]

B. [tex]\( y + 2x + x + y = 9 \)[/tex]

C. [tex]\( y = 2x + 9 \)[/tex]

D. [tex]\( x + 2x = 9 \)[/tex]



Answer :

Sure, let's solve the problem step-by-step:

1. We are given two equations:
[tex]\[ y = 2x \][/tex]
[tex]\[ x + y = 9 \][/tex]

2. In the second equation, [tex]\( x + y = 9 \)[/tex], we need to substitute the value of [tex]\( y \)[/tex] from the first equation. Since [tex]\( y = 2x \)[/tex], we replace [tex]\( y \)[/tex] in the second equation with [tex]\( 2x \)[/tex]:
[tex]\[ x + 2x = 9 \][/tex]

So the first step in the substitution problem is:

d. [tex]\( x + 2x = 9 \)[/tex]