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Basile [38]
3 years ago
11

-7 + y = -19 -2x + 3y = -19

Mathematics
2 answers:
Natasha2012 [34]3 years ago
8 0

Answer:

y = -12, x = -17/2 or -8\frac{1}{2}

Step-by-step explanation:

-7 + y = -19 . . . . . . .. . eq1

-2x + 3y = -19  . . . . . . .eq 2

solve for y in eq 1

that is y = -19 + 7

          y = -12

substitute y into eq 2.

-2x + 3(-12) = -19

-2x - 36 = -19

-2x = -19 + 36

-2x = 17

x = -17/2 or -8\frac{1}{2}

Zinaida [17]3 years ago
3 0
If you want to solve the system of equations it will be:

Step 1: solve the equation for y

y= -19+7 → y= -12

Step 2: substitute y into the equation

-2x+3x(-12)=-19

Step 3: solve the equation for x

x= -17/2

Step 5: the possible solution is the order pair (x,y)

Answer: (-17/2 , -12)
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At 2 PM, a thermometer reading 80°F is taken outside where the air temperature is 20°F. At 2:03 PM, the temperature reading yiel
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Use Law of Cooling:
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T0 = initial temperature, TA = ambient or final temperature

First solve for k using given info, T(3) = 42
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Substituting k back into cooling equation gives:
T(t) = 60(\frac{11}{30})^{t/3} + 20

At some time "t", it is brought back inside at temperature "x".
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The new cooling equation for when its back inside is:
T(t) = (x-80)(\frac{11}{30})^{t/3} + 80 \\  \\ 71 = (x-80)(\frac{11}{30})^{\frac{10-t}{3}} + 80
Solve for x:
x = -9(\frac{11}{30})^{\frac{t-10}{3}} + 80
Sub back into original cooling equation, x = T(t)
-9(\frac{11}{30})^{\frac{t-10}{3}} + 80 = 60 (\frac{11}{30})^{t/3} +20
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In triangle △ABC, ∠ABC=90°, BH = altitude
Ainat [17]

Answer: The exact length of segment HC is sqrt(3) units

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==============================================

Work Shown:

Let x = length of HC

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Draw out the picture. This step is optional but helpful in my opinion. The drawing is attached below.

After adding in the altitude BH, we have three similar triangles. So we can form the proportion shown below to solve for x

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