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3 years ago

-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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Alexeev081 [22]

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First solve for k using given info, T(3) = 42
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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

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

The approximate length is roughly 1.73205080756888 (round that however you need to)

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

Work Shown:

Let x = length of HC

Since AH = 3*HC, this means AH = 3*x

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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