How do you solve this <br> 21 = 14 + 7x

Which values for A and B will create infinitely many solutions for this system of equations? ax-y=8 2x+y=b

Nata [24]

Answer:

a = -2 , b = -8

Step-by-step explanation:

* Lets talk about the solution of the linear equations

- There are three types of the solutions of the system of linear equations

# If the two lines intersect each other, then there is one solution

- The equations are ax+ by = c , dx + ey = f

# If the two lines parallel to each other, then there is no solution

- The equations are ax+ by = c , ax + by = d in its simplest form ,

where a is the coefficient of x , b is the coefficient of y and

c , d are the numerical terms

# If the two lines coincide (over each other), then there are infinite

solutions

- The equations are ax+ by = c , ax + by = c in its simplest form, where

a is the coefficient of x , b is the coefficient of y and c is the

numerical term

* Lets solve the problem

∵ The system of equation is:

ax - y = 8 ⇒ (1)

2x + y = b ⇒ (2)

∵ The system create infinitely many solutions

∴ The lines are coincide

- The equations must be equal, then multiply equation(1) or (2) by -1 to

make the coefficient of y in the two equations equal

∴ -ax + y = -8

∴ 2x + y = b

∵ Their coefficients of x are equal

∵ Their coefficients of y are equal

∵ Their numerical terms are equal

∵ The coefficient of x in equation (1) is -a and in equation (2) is 2

∴ -a = 2 ⇒ multiply both sides by -1

∴ a = 2

∵ The numerical term in equation (1) is -8 and in equation (2) is b

∴ b = -8

* The values for a and b will create infinitely many solutions are -2 , -8

5 0

3 years ago

Describe and correct the error the student made when writing the equation of the line that passes through (-8,5)

pshichka [43]

Option D (The student should have used as the slope of the perpendicular line.) is correct.

Step-by-step explanation:

We need to identify the error that the student made in finding equation of the line that passes through (-8,5) and is perpendicular to y = 4x + 2

The slope of the required line would me -1/m because both lines are perpendicular.

So, slope of new line will be: -1/4

because the equation of slope-intercept form is: $y=mx+b$ where m is the slope

Now, for finding equation the student used point slope form i.e $y-y_1=m(x-x_1)$

where y_1 and x_1 are the points and m is the slope.

Putting values:

x_1=-8, y_1=5 and m=-1/4

$y-5=-\frac{1}{4}(x-(-8))\\y-5=-\frac{1}{4}(x+8)\\y-5=-\frac{1x}{4}-2\\y=-\frac{1x}{4}-2+5\\y=-\frac{1x}{4}+3$

This is the correct solution.

The student made error by using the wrong slope he used 2 instead of -1/4

in the step $y-5 = 2(x-(-8))$

So, Option D (The student should have used as the slope of the perpendicular line.) is correct.

Keywords: Equation of line using Slope

Learn more about Equation of line using Slope at:

#learnwithBrainly

3 0

2 years ago

Read 2 more answers

Help with this one its 1 problem

Rainbow [258]

Answer: Alberto caught up to Omar after 6 seconds, when Alberto had to run 54 meters.

Step-by-step explanation:

4 0

2 years ago

A large envelope is 0.085 cm thick. How thick would a stack of 100 of these envelopes be? Explain your reasoning.

Pavlova-9 [17]

Answer:

8.5 cm

Step-by-step explanation:

I think because wouldn't you take the 0.085 · 100

(get mad if I'm wrong i might be)

3 0

2 years ago

Jim will rent a car for the weekend. He can choose one of two plans. The first plan has an initial fee of $ 59 and costs an addi

AveGali [126]

Answer:This problem is about linear equations. We assume Dale drive X miles, and the total cost is $Y, then we can get:

Plan I: Y=38+0.11X

Plan II: Y=49+0.07X

When both plans cost the same, 38+0.11X=49+0.07X. We will get X = 275miles, and Y=$68.25

Step-by-step explanation:

6 0

2 years ago

How do you solve this 21 = 14 + 7x