Answer:
<u>10°C average temperature</u>
Step-by-step explanation:
Average Temperature = Lowest + 17
= -7 + 17
= 17 - 7
= <u>10°C average temperature</u>
Using the given information, we can say the following:
Width (W) = x
Length (L) = (2x - 4)
Area of Rectangle = L × W
Using this, we can formulate an equation for rectangle in question:
x(2x - 4) = 30
Expand and move everything to one side:
2x² - 4x - 30 = 0
Simplify by dividing everything on both sides by 2:
x² - 2x - 15 = 0
Factorise:
(x + 5)(x - 3) = 0
Set each factor equal to 0 and solve for x:
x + 5 = 0
x = -5 (a dimension cannot be negative so this is not the solution we want)
x - 3 = 0
x = 3 (this is the solution)
x = W = 3"
L = 2x - 4
L = 2(3) - 4
L = 2"
So, the length the rectangle is 2" and the width is 3"
Multiply x<span> and </span>3
<span>Multiply x and 1</span>
<span>The x just gets copied along.</span>
<span>The answer is x</span>
x
<span>3*x evaluates to 3x</span>
Because of the minus sign
<span>3x becomes - 3x</span>
<span>The answer is -3x</span>
<span>Multiply y and 2</span>
<span>Multiply y and 1</span>
<span>The y just gets copied along.</span>
<span>The answer is y</span>
y
<span>2*y evaluates to 2y</span>
<span>-3*x-2*y evaluates to -3x-2y</span>
<span>The answer is -3x-2y-2</span>
<span>-3*x-2*y-2 evaluates to <span>-3x-2y-2</span></span>
<span><span>so the first one is right</span></span>
<span><span>
</span></span>
The last two would be your answer :)
