The cost per foot of redwood and of pine is $3.5 and $1.5 respectively.
let
50x + 70y = 280
100x + 60y = 440
Multiply (1) by 2
100x + 140y = 560
subtract to eliminate x
80y = 120
y = 120/80
y = $1.5
substitute y = 1.5 into (1)
50x + 70(1.5) = 280
50x + 105 = 280
50x = 280 - 105
50x = 175
x = 175 / 50
x = $3.5
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Answer:
d
Step-by-step explanation:
Using the rule of exponents
= , then
= =
its b