Answer
x=-2 and y=-3
Step-by-step explanation:
Step: Solvey=5x+7for y:
Step: Substitute5x+7 for y in 3x+y=−9:
3x+y=−9
3x+5x+7=−9
8x+7=−9(Simplify both sides of the equation)
8x+7+−7=−9+−7(Add -7 to both sides)
8x=−16
8x/8=−16/8
(Divide both sides by 8)
x=−2
Step: Substitute−2 for x in y=5x+7:
y=5x+7
y=(5)(−2)+7
y=−3(Simplify both sides of the equation)
Answer:
1.42 hours
Step-by-step explanation:
In this case we must take into account that the speed would be to fill a pool for a time, that this case is in hours, therefore it would be like this:
1/5 for the first pipe
1/2 for the second pipe
Now, we will use both at the same time, therefore:
1/5 + 1/2 = 1 / x
0.7 = 1 / x
x = 1 / 0.7
x = 1.42
That is to say that if we use both we will take a total of 1.42 hours
Answer:
2 equivalent expressions w/ negative signs in different places.
a) 
=-1/5 x and x/-5
b) 
=14/-y and -14/1/y
c) 
=a/1/b and 1/b/1/a
d) 
=-c/y and -c/1/y
This =2.4 I hope that this helps you
The system of equations representing these costs are; y = 7.5x and y = 5.5x + 10
<h3>How to find the equation of a line?</h3>
The slope of the first line is;
m = (y2 - y1)/(x2 - x1)
m = (32 - 10)/(4 - 0)
m = 5.5
Now, the first coordinate has a y-intercept of 10. Thus, the equation here for the cost is; y = mx + c = 5.5x + 10
The slope of the second line is;
m = (y2 - y1)/(x2 - x1)
m = (15 - 0)/(2 - 0)
m = 7.5
Now, the first coordinate has a y-intercept of 0. Thus, the equation here for the cost is; y = mx + c = 7.5x + 0 = 7.5x
Thus, the system of equations representing these costs are;
y = 7.5x and y = 5.5x + 10
Read more about Equation of a line at; brainly.com/question/13763238
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