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PtichkaEL [24]
4 years ago
8

Solve using the substitution method -7x+y =42 and 5x+13y =66

Mathematics
1 answer:
leva [86]4 years ago
5 0
-7x+y=42
y=42+7x 

5x+13y=66
Substitute for y (meaning put 42+7x into the equation above instead of y because they are equal - see second line of my answer above)

5x+13[42+7x]  = 66
5x +546 = 66
5x=66-546
5x=-480
x=-480/5
x=-96

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The set of ordered pairs below represents a linear function.
Doss [256]
Pretty sure ( -2,-7) because from -1 you go over one then each y is going down 3 so -4 - 3 is -7
8 0
3 years ago
Find the area of this figure. Brainliest to first correct answer. Tysm
larisa [96]
Area of Triangle:
A = 1/2 bh = 1/2 (5)(12) = 30 m^2

Area of semicircle:
A = 1/2 π r^2 = 1/2 π 6^2 = 18<span>π m^2

Area of figure = </span>Area of semicircle + Area of Triangle 
Area of figure = 18π  + 30 m^2

Answer is C.
18π  + 30 m^2
5 0
3 years ago
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Re write the statement 19+7 divided by 2-5 by including one pair of brackets to make the total equal to 8
Oksanka [162]

Answer:

The solution is given below:

Step-by-step explanation:

The computation is shown below:

= 19 +  7 divided by 2 - 5

= (19 + 7) ÷ (2) - 5

= 26 ÷ 2 - 5

= 13 - 5

= 8

Hence, after solving this the value would be 8

Therefore it is equal to the 8

Hence, the given statement is true

6 0
3 years ago
To test the belief that sons are taller than their​ fathers, a student randomly selects 13 fathers who have adult male children.
KATRIN_1 [288]

Answer:

1) B. The differences are normally distributed or the sample size is large

C. The  sample size mus be large

E. The sampling method results in an independent sample

2) The null hypothesis H₀:  \bar x_1 =  \bar x_2

The alternative hypothesis Hₐ: \bar x_1 <  \bar x_2

Test statistic, t = -0.00693

p- value = 0.498

Do not reject Upper H₀ because, the P-value is greater than the level of significance. There is sufficient evidence to conclude that sons are the same height as their fathers  at 0.10 level of significance

Step-by-step explanation:

1) B. The differences are normally distributed or the sample size is large

C. The  sample size mus be large

E. The sampling method results in an independent sample

2) The null hypothesis H₀:  \bar x_1 =  \bar x_2

The alternative hypothesis Hₐ: \bar x_1 <  \bar x_2

The test statistic for t test is;

t=\dfrac{(\bar{x}_1-\bar{x}_2)}{\sqrt{\dfrac{s_{1}^{2} }{n_{1}}-\dfrac{s _{2}^{2}}{n_{2}}}}

The mean

Height of Father, h₁,  Height of Son h₂

72.4,      77.5

70.6,      74.1

73.1,       75.6

69.9,      71.7

69.4,      70.5

69.4,      69.9

68.1,       68.2

68.9,      68.2

70.5,       69.3

69.4,       67.7

69.5,       67

67.2,       63.7

70.4,       65.5

\bar x_1  = 69.6      

s₁ = 1.58

\bar x_2 = 69.9

s₂ = 3.97

n₁ = 13

n₂ = 13

t=\dfrac{(69.908-69.915)}{\sqrt{\dfrac{3.97^{2}}{13}-\dfrac{1.58^{2} }{13}}}

(We reversed the values in the square root of the denominator therefore, the sign reversal)

t = -0.00693

p- value = 0.498 by graphing calculator function

P-value > α Therefore, we do not reject the null hypothesis

Do not reject Upper H₀ because, the P-value is greater than the level of significance. There is sufficient evidence to conclude that sons are the same height as their fathers  at 0.10 lvel of significance

8 0
4 years ago
I need help but it’s easy i’m just dumb
vfiekz [6]

Answer:

40

Step-by-step explanation:

a^2+b^2=c^2

3 0
3 years ago
Read 2 more answers
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