Answer:
The length of the longer piece is 70 cm
Explanation:
Let
x ----> the length of the longer piece
y ---> the length of the shorter piece
we know that
[tex]x+y=100[/tex] ----> equation A
[tex]x=2y+10[/tex] ----> equation B
substitute equation B in equation A
[tex]2y+10+y=100[/tex]
Solve for y
[tex]2y+y=100-10[/tex]
[tex]3y=90[/tex]
[tex]y=30\ cm[/tex]
Find the value of x
[tex]x=2y+10[/tex] ----> [tex]x=2(30)+10=70\ cm[/tex]
therefore
The length of the longer piece is 70 cm