HELP I DONT GET IT!!!For the system below solve using linear combinations method 2a+3b=1 and -2a+b=11

Mathematics

2 answers:

son4ous [18]3 years ago

6 0

Because it using subtraction on one and multiply on the other

Maksim231197 [3]3 years ago

3 0

Linear combination method just means to add the equations so that one variable with cancel. In this case the a values are already set up so that they will cancel.
2a + 3b = 1
-2a + b = 11
4b = 12
b = 3

now put 3 back into either of the original equations and solve for a.
2a + 3(3) = 1
2a + 9 = 1
2a = -8
a = -4
(-4,3)

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inna [77]

Answer:

The height of the tree = 25 feet

Step-by-step explanation:

From the given diagram : EF = 5 feet, FA = 8 feet, CA = 40 feet

∠AFE = 90° and ∠ACB = 90°

To find : CB, the height of the tree.

Solution : In ΔAEF and ΔAB C

∠AFE = ∠ACB = 90°

∠A is common angle.

So, By AA postulate of similarity of triangle, ΔAEF ~ ΔABC

Now, sides of similar triangles are proportional to each other

$\implies\frac{FA}{CA}=\frac{EF}{CB}\\\\\implies \frac{8}{40}=\frac{5}{CB}\\\\\implies CB=\frac{40\times 5}{8}\\\\\implies CB=25$

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3 years ago

I learn maths and I don't know how to solve this problem.

Lyrx [107]

Answer:

As we get closer to x=-3, the limit is approaches -1, on both sides of -3 so this is a good limit so c is 8.

Step-by-step explanation:

In order for a limit to exists, the left side limit must exist and right side limit must exist and on top of that, they must be equal to each other.

In this case, this a piece wise function and by definition of a limit that exist, the limit of this piece wise function as x approaches 3 from either side, must be equal.

We let x=-3 for the top equation.

$( - 3) {}^{2} - 10 = - 1$