Linear Systems Problem:
The length of a rectangle is 9.7 cm more than 4 times the width. The perimeter of the rectangle is 91.4 cm. Write and solve a system of linear equations to represent the situation.

I got my equations as l=9.7+4w and 2l+2w=91.4 (l=length, w=width) but now I'm not sure whether to use substitution or elimination?

Question

Linear Systems Problem:
The length of a rectangle is 9.7 cm more than 4 times the width. The perimeter of the rectangle is 91.4 cm. Write and solve a system of linear equations to represent the situation.

I got my equations as l=9.7+4w and 2l+2w=91.4 (l=length, w=width) but now I'm not sure whether to use substitution or elimination?

texaschic101 · Answer

I would use substitution. Just sub in 4W + 9.7 in for l in the other equation
2l + 2W = 91.4
2(4W + 9.7) + 2W = 91.4
can you finish from here ?

razzanide · Answer

2(4W + 9.7) + 2W = 91.4
8w+19.4+2w=91.4
10w=72
w=7.2

9.7+4(7.2)=l
9.7+28.8=l
38.5=l

l=38.5; w=7.2

texaschic101 · Answer

looks good...you can check it by subbing your info back into either equation
2l + 2W = 91.4
2(38.5) + 2(7.2) = 91.4
77 + 14.4 = 91.4
91.4 = 91.4 (correct)