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2 years ago

How can you decide which variable to solve for first when you are solving a linear system by substitution

1 answer:

7 0

There are many factors, it is all a matter of preference, normally, you want to try to solve for the easiest one to get to
example

if y ou had

(x-3)^2+y=9
you would solve for y becuase it is less tricky

it is all a matter of preference

You might be interested in

How do I solve this?

serg [7]

Answer:

(x, y) = (18, 5)

Step-by-step explanation:

Assuming the three lines meet at a single point at lower left (the figure is sloppily drawn), the angle (3x)°+49° is a corresponding angle to (7x-23)°. That means they have the same measure:

3x +49 = 7x -23

72 = 4x . . . . . . . . . add 23-3x

18 = x . . . . . . . . . . . divide by 4

Angles (3x)° and (11y-1)° are "corresponding" angles, so are congruent.

3x = 11y -1

3(18) +1 = 11y . . . . add 1, fill in the value of x

55/11 = y = 5 . . . . divide by 11

The values of x and y are 18 and 5, respectively.

5 0

3 years ago

Does anyone get this?

stepladder [879]

Answer: B

Step-by-step explanation:

In the systems of equation it already gives you the solution for x which is -2 so all you have to do is substitute -2 into the first equation and solve for y.

y= 2/3x + 3

x= -2

Substitute x for -2

y = $\frac{2}{3}* \frac{-2}1} + 3$

y= $\frac{-4}{3}$ + $\frac{3}{1}$

y = $\frac{5}{3}$

so now you have the solution like this $(-2,\frac{5}{3})$

8 0

3 years ago

Points A, B, and C are collinear. Point B is between A and C. Find the length indicated. AB= 5x-15, BC=3x-5, and AC=28. Find AB

katrin2010 [14]

Answer: AB is 15

Step-by-step explanation: First, you need to draw a picture and label the parts of the line: AB=5x-15; BC= 3x-5; AC =28. Because of the segment addition postulate, you set the equation to be 5x-15+3x-5=28. Then you solve:

5x-15+3x-5=28

Add like terms:

8x-20=28

Add 20 to both sides

8x=48

Divide by 8

x=6

Now, you need to find the measure of AB, so you plug the 6 into the x variable for 5x-15

5(6)-15

30-15

AB=15

4 0