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3 years ago

Solve by the linear combination method (with or without multiplication). x + y = 40 0.08x + 0.03y = 1.7

1 answer:

4 0

That's also known as the addition method.
x + y = 40
.08x+.03y=1.7
We need to multiply the top equation by either a -.08 or a -.03 to eliminate one of the variables. Let's get rid of the y:
-.03(x + y) = -.03(40) which gives us

-.03x - .03y = -1.2
.08x + .03y = 1.7
When we add those together we are left with .05x = .5 and x = 10. If we sub that 10 in for x into the first equation (either would have worked but the first one is way easier to work with!) we get 10 + y = 40 and y = 30. So the solution to the system is (10, 30)

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Determine the measure of angle A

igor_vitrenko [27]

Answer:

63*

Step-by-step explanation:

The first thing you need to do is find the value of x. What I did for this was trial and error. I tried a number, and if it was too big, I tried a smaller one. If you add up all of the angles, it should equal up to 180*, so I kept on doing this until I added up to 180.

The answer I got was x=8, so I plugged this into the equation for A and solved. 9x8 is 72, and 72-9 is 63.

Therefore, 63 is the correct answer.

6 0

3 years ago

The probability of Tina's winning a tennis game is 75%. What is the probability that Tina will lose a game A 10% B 25% C 50% D 7

Flauer [41]

Answer:

The correct answer is B. 25%

Step-by-step explanation:

If Tina's probability of winning a tennis game is 75%, therefore:

(100% - 75%) = Probability that Tina will lose a game

25% = Probability that Tina will lose a game

The correct answer is B. 25%

6 0

3 years ago

A, B, and C are polynomials, where A = n, B = 2n + 6, and C = n2 – 1. What is AB – C in simplest form? A=–n2 + 3n + 5 B=n2 + 6n

slava [35]

Answer: B: n^2+6n+1

Step-by-step explanation:

A=n

B=2n+6

C=n^2-1

AB-C

n(2n+6)-n^2-1

2n^2+6n-n^2+1

n^2+6n+1

4 0

3 years ago

Read 2 more answers

How do I find the domain and range of a graph?

tia_tia [17]

The domain is the x-axis and the range is the y-axis.

To find the domain, you measure or count the widest part of this oval horizontally. So that is 3 units to the right of 0 and 3 units to the left of 0. I counted it exactly on the axis because that is the widest part of the oval.

To find the range, you again count or measure the widest part of the oval vertically. So that is 4 units above 0 and 4 units below 0.

Final Answer

D: -3 ≤ x ≤ 3

R: -4 ≤ x ≤4

7 0

4 years ago

Solve (x + 4)2 – 3(x + 4) – 3 = 0 using substitution. u = Select the solution(s) of the original equation.

bezimeni [28]

Answer:

$\dfrac{-5-\sqrt{21}}{2},\ \dfrac{-5+\sqrt{21}}{2}$

Step-by-step explanation:

For the equation $(x+4)^2-3(x+4)-3=0$ use the substitution $u=x+4.$ Then the equation will take look

$u^2-3u-3=0.$

Solve this quadratic equation:

$D=(-3)^2-4\cdot 1\cdot (-3)=9+12=21,\\ \\u_{1,2}=\dfrac{-(-3)\pm \sqrt{21}}{2}=\dfrac{3\pm\sqrt{21}}{2}.$

Thus,

$x+4=\dfrac{3-\sqrt{21}}{2}\text{ or }x+4=\dfrac{3+\sqrt{21}}{2},\\ \\x_1=\dfrac{3-\sqrt{21}}{2}-4=\dfrac{-5-\sqrt{21}}{2}\text{ or }x_2=\dfrac{3+\sqrt{21}}{2}-4=\dfrac{-5+\sqrt{21}}{2}.$

8 0

4 years ago

Read 2 more answers