All categories

3 years ago

X=17-4y y=x-2 answer by substitution

Mathematics

1 answer:

GaryK [48]3 years ago

5 0

Answer:

(5,3)

Step-by-step explanation:

x=17-4y

x=17-4x+8

x=25-4x

5x=25

x=5

y=x-2

y=5-2

y=3

(5,3)

You might be interested in

Your family goes to a Southern-style restaurant for dinner. There are 7 people in your family. Some order the chicken dinner for

butalik [34]

Answer:

a) 4 people ordered streak dinner

b) 3 people ordered chicken dinner

Step-by-step explanation:

Let the number of people that ordered steak dinner be x

and the number of people that ordered chicken dinner be y

From the question,

There are 7 people in your family

Hence, we can write that

x + y = 7 ...... (1)

Also from the question

Some order the chicken dinner for $13 and some order the steak dinner for $18 and the total bill was $111.

We can then write that

13y + 18x = 111 ...... (2)

From equation (1)

x + y = 7

Then,

x = 7 - y ...... (3)

Put this into equation (2)

13y + 18x = 111

13y + 18(7 - y) = 111

13y + 126 - 18y = 111

-5y = -15

5y = 15

y = 15 / 5

y = 3

Put the value of y into equation (3) to get x

x = 7 - y

Then

x = 7 - 3

x = 4

Hence, 4 people ordered streak dinner

and 3 people ordered chicken dinner

a) 4 people ordered streak dinner

b) 3 people ordered chicken dinner

3 0

2 years ago

Find the discriminant and determine the nature of the roots to the quadratic equation

Katen [24]

№17
$x^{2} +6x-7=0 \\ D=6 ^{2} -4*(-7)=36+28=64=8 ^{2} \\ \\ x_{1} = \frac{-6+8}{2} =1 \\ \\ x_{2} = \frac{-6-8}{2} =-7$
Answer: x₁ = 1
   x₂ = - 7

№18
$2 x^{2} -3x+4=3 \\ 2 x^{2} -3x+4-3=0 \\ 2 x^{2} -3x+1=0 \\ \\ D= -3 ^{2} -4*2=9-8=1 \\ \\ x_{1} = \frac{3+1}{2*2} = \frac{4}{4} =1 \\ \\ x_{2} = \frac{3-1}{2*2} = \frac{2}{4} =0.5$
Answer: x₁ = 1
     x₂ = 0,5.

№19
$2 x^{2} -4x-5=0 \\ D=-4 ^{2} -4*2*(-5)=16+40=56 \\ \\ x_{1}= \frac{4+ \sqrt{56} }{2*2} = \frac{4}{4} + \sqrt{ \frac{56}{16} } =1+ \sqrt{3.5} \\ \\ x_{2} = \frac{4- \sqrt{56} }{2*2} = \frac{4}{4} - \sqrt{ \frac{56}{16} } =1- \sqrt{3.5} 
$
Answer: x₁ = 1 + √3.5
     x₂ = 1 - √3.5

3 0

3 years ago

What are the coordinates of point H? On a coordinate plane, point H is 1.5 units to the left and 3 units up. (Negative 3, 1 and

Vesna [10]

Answer:

Option 2 (B)

Step-by-step explanation:

5 0

2 years ago

Read 2 more answers

Solve the quadratic equation 3x²-3x-1=0?<br>(by using the square method)

ohaa [14]

Answer:

x=1 and x=-1/3

Step-by-step explanation:

$3x^2-2x-1=0\\\\3(x^2-\frac{2}{3}x-\frac{1}{3})=0\\ \\3(x^2-\frac{2}{3}x-\frac{1}{3}+\frac{4}{9})=3(\frac{4}{9})\\ \\ 3(x^2-\frac{2}{3}x+\frac{1}{9})=\frac{4}{3}\\ \\ 3(x-\frac{1}{3})^2=\frac{4}{3}\\ \\(x-\frac{1}{3})^2=\frac{4}{9}\\ \\x-\frac{1}{3}=\pm\frac{2}{3}$