Question 150588
A) 2L+b=70
B) L=2b-5
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A) 
2(2b-5)+b=70 Substitute 2b-5 for L.
4b-10+b=70
5b=80
b=16 dm
.
B) 
L=2*16 -5
=27 dm
.
27+27+16=70
.
Ed