Step-by-step explanation:
Example: -2+-5
It can also be written as -2-5.
How I do these problems, I do 2+5, which is 7. Then I add a negative sign. So -2+-5 or -2-5 is equal to -7.
-a+-b can also be written as -a-b. So yes, if a and bare negative, then a + b is also negative.
hope it helps!
The walkway is 1.5 m wide.
The area of the pool is 12(6) = 72 m².
Adding a walkway of unknown width, x, around all 4 sides of the pool increases the width by 2x and the length by 2x; thus the area of the entire pool and walkway together would be given by
(12+2x)(6+2x)
We know that the area of just the walkway is 9 m² less than the area of the pool. This means that:
(12+2x)(6+2x)-72 = 72-9
Multiplying through we have:
12*6+12*2x+2x*6+2x*2x - 72 = 63
72 + 24x + 12x + 4x² - 72 = 63
24x + 12x + 4x² = 63
36x + 4x² = 63
Writing in standard form we have:
4x² + 36x = 63
We want to set it equal to 0 to solve, so subtract 63 from both sides:
4x² + 36x - 63 = 63 - 63
4x² + 36x - 63 = 0
Using the quadratic formula,

Since a negative width makes no sense, the walkway is 1.5 m wide.
Replace x in the second equation with the value of x from the first one.
x = -3y
x + y = -6
-3y + y = -6
Simplify:
-2y = -6
Divide both sides by -2:
y = -6 / -2
y = 3
Now replace Y with 3 in one of the equations to solve for x:
x = -3y = -3(3) = -9
X = -9, Y = 3
(-9,3)
The time that he studies is the independent variable because you can change that time amount , and the test score / points depend on how long he studies.
S = 3H
^ test score = amount of hours x three points
Step-by-step explanation:
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