2 years ago

What is the elimination of 20x+5y=120 and 10x+7.5=80

1 answer:

5 0

20x+5y=120
10x+7.5y=80 multiply this one by 2
___________

20x+5y=120
20x+15y=160 subtract

___________

-10y=-40 divide both sides by -10
____________

y=4

20x+5(4)=120 plug 4 in for y in the first equation
20x+20=120 multiply
20x=100 subtract
x=5 divide to find x

You might be interested in

What is the GCF of 16s3t, 40s5, and 68t2? 4 4s3t 8 8s3t

Gemiola [76]

4 is the only factor common among all terms

3 0

2 years ago

Read 2 more answers

The dot plot shows how many games of chess 8 different members of the chess club played in one month. If Jackson is a new member

stira [4]

Answer:

Step-by-step explanation:

8 0

2 years ago

In the derivation of the quadratic formula by completing the square, the equation (x+b over 2a)^2=-4ac+b^2 over 4a^2 is created

vredina [299]

Answer:

The result of applying the square root property of equality to this equation is $x=\dfrac{-b\pm \sqrt{b^2-4ac}}{2a}$ .

Step-by-step explanation:

Consider the provided equation.

$\left(x+\dfrac{b}{2a}\right)^2=\dfrac{-4ac+b^2}{4a^2}$

As the above equation is formed by perfect square trinomial so simply applying the square root property as shown:

$\sqrt{(x+\dfrac{b}{2a})^2}=\pm \dfrac{\sqrt{-4ac+b^2}}{\sqrt{4a^2}}\\x+\dfrac{b}{2a}=\pm \dfrac{\sqrt{b^2-4ac}}{2a}$

Isolate the variable x.

$x=-\dfrac{b}{2a}\pm \dfrac{\sqrt{b^2-4ac}}{2a}\\x=\dfrac{-b\pm \sqrt{b^2-4ac}}{2a}$

Hence, the result of applying the square root property of equality to this equation is $x=\dfrac{-b\pm \sqrt{b^2-4ac}}{2a}$ .

4 0

1 year ago

Read 2 more answers

Kim solved the equation below by graphing a system of equations. log2(3x-1)= log4(x+8) What is the approximate solution to the e

kifflom [539]

Answer:

(1.35, 1.6)

Step-by-step explanation:

A screenshot of the graph is attached.

Once we graph the equations $y=\log_2(3x-1)$ and $y=\log_4(x+8)$ , the solution to this system will be their intersection point.

Tracing the graph on the calculator, we see that the point of intersection is at about (1.35, 1.6).

6 0

2 years ago

Read 2 more answers

In a class of 20 students, 7 were wearing a white shirt. In the same class, 14 students had on blue jeans. Eyewitnesses all stat

nadezda [96]

Answer:

I want to answer 15%

Step-by-step explanation:

As for how to solve it I don't really know I would use process of elimination because the answer can't be so high that it's 45% so that's out. Personally I think that 35% is pretty high to so my best educated guess would be between 25% and 15% . Sorry this isn't more helpful.

6 0

2 years ago