Answer:
x = 31.2
Step-by-step explanation:
x - 19.7 = -4.1
x = 15.6 --- add 19.7 to both sides to get rid of -19.7
x = 31.2 --- multiply both sides by 2 to get rid of 
They consists of equations and unknown variables. There are 4 PCs and 8 Mac in the room
<h3>System of equation</h3>
They consists of equations and unknown variables
Let the number of PCs be x
Let the number of Mac be y
If Mke has 12 computers, then;
x + y = 12
If there are two Macs for every PC in his classroom, then;
y = 2x
Substitute
x + 2x = 12
3x = 12
x = 4
Recall y = 2x
y = 2(4)
y = 8
There are 4 PCs and 8 Mac in the room
Learn more on system of equations here; brainly.com/question/14323743
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Y = x + 6
y = -3x + 6
put the system of linear equations into standard form
x - y = -6
-3x - y = -6
solution:
x = 0
y = 6
Answer:
Its A or the first option
Step-by-step explanation:
good luck
Answer:
- boat: 16 mph
- current: 4 mph
Step-by-step explanation:
speed = distance / time
The rate downriver is (60 mi)/(3 h) = 20 mi/h.
The rate upriver is (60 mi)/(5 h) = 12 mi/h.
The rate of the boat in still water is the average of these:
(20 +12)/2 mi/h = 16 mi/h
The rate of the current is the difference between the boat speed and actual speed:
16 mi/h - 12 mi/h = 4 mi/h