The answer is 45
2x+45+x=180
3x+45=180
3x=135
X=45
The dependent variable is f(m)...total money earned per day
the independent variable is m...number of miles
f(m) = 3.5m + 65
for 40 miles..
f(40) = 3.5(40) + 65
= 140 + 65
= 205 <== money earned for the day
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the dependent variable is f(p)....total charged
the independent variable is p...the number of pounds
f(p) = 3.5p
for 5 lbs...
f(5) = 3.5(5)
f(5) = 17.50 <== total that was charged
Answer:
however the meaning of math
Step-by-step explanation:
20+20
Knowing that cos(45°) = 1/√2 is the way forward.

The last step in the equation may not be obious, but the trick here is to multiple numerator and denominator with (1-√2), then the denominator has the special product (a+b)(a-b) = a²-b².