Answer:
Like terms
Same number of equations as unkowns
Step-by-step explanation:
To add linear equations you need the amount of equations to match the number of unknowns.
The equations must have like terms.
All like terms will be added to each other and might even cancel out and solve one term if equal terms have opposite signs.
Answer:
$120
Step-by-step explanation:
Set the cost of the article pre-tax as x.
<em>x + 0.15x = 138</em>
<em>1.15x = 138</em>
<em>x = 138/1.15</em>
<em>x = </em><u><em>$120</em></u>
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Answer: the cost of the article without taxes is <u>$120</u>.
Answer:
The speed in still water is 5 miles per hour.
Step-by-step explanation:
distance with current = 90 miles
distance against current = 10 miles
speed in still water = s
speed of current = 4 mph
speed with current = s + 4
speed against current = s - 4
time = t
speed = distance/time
distance = speed * time
With current:
90 = (s + 4) * t
Against the current:
10 = (s - 4) * t
We have a system of equations:
90 = (s + 4) * t
10 = (s - 4) * t
90 = ts + 4t
10 = ts - 4t
Subtract the second equation from the first equation.
80 = 8t
10 = t
t = 10
10 = t(s - 4)
10 = 10(s - 4)
1 = s - 4
s = 5
Answer: The speed in still water is 5 miles per hour.
Answer:
7=150
Step-by-step explanation:
Each lap is worth $7, so if Mu walked laps and the total is $150, then the equation would be
7=150
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