Answer:
x = 6, y =3
Step-by-step explanation:
4x-7y=3
x-7y=-15
Multiply the first equation by -1
-4x+7y=-3
Then add this to the second equation to eliminate y
-4x+7y=-3
x-7y=-15
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-3x +0y = -18
-3x = -18
Divide by -3
-3x/-3 = -18/-3
x = 6
Now find y
x -7y = -15
6 -7y = -15
Subtract 6 from each side
6-7y-6 = -15-6
-7y = -21
Divide by -7
-7y/-7 = -21/-7
y =3
The sum of two numbers
x + y = 21
x = smaller number
y = larger number
Larger Number = y = (2x -6)
Substitute (2x - 6) for y
x + y = 21
x + (2x - 6) = 21
3x - 6 = 21
3x = 21 + 6
3x = 27
3x / 3 = 27 / 3
x = 9
Smaller number = x = 9
Find the larger number by inserting 9 into (2x - 6)
(2x - 6)
(2(9) - 6)
18 - 6
12
So
x = 9
y =12
Check our answer by inserting x = 9 and y = 12 into x + y = 21
x + y =21
9 + 12 = 21
21 = 21
So since we have 21 = 21 we know our answer is correct.
Answer:
The cost is y = $185
Step-by-step explanation:
Let us have points spelt out here
(2500,125) and (3200,146)
The general form of a straight line equation is;
y = mx + b
where m is slope
So to calculate the slope in this case, we have
m = (146-125)/(3200-2500)
m = 21/700 = 0.03
So we have the equation as
y = 0.03x + b
To get b, we use any of the two points
Let us use (2500,125)
So we have
125 = 0.03(2500) + b
125 = 75 + b
b = 125-75
b = 50
So the complete equation of the line is;
y = 0.03x + 50
So here, we want to find the cost of a house with 4500 square feet
simply substitute 4,500 for x
y = 0.03(4500) + 50
y = 135 + 50
y = $185
Answer:
1/4
Step-by-step explanation:
