All categories

3 years ago

3x-4y=8 18x-5y=10 What is the answer to this

Mathematics

1 answer:

trapecia [35]3 years ago

7 0

Answer:

x=0;y=-2

Step-by-step explanation:

multiply first equation by 6: 18x-24y=48

Subtract 2nd equation from 1st: -19y=38

y=-2

Sub into 1st equation: 3x-4(-2)=8

3x+8=8

3x=0

Therefore, x=0;y=-2

You might be interested in

What is the value of t in the equation 3(2t + 5) = 5t + 25?

11Alexandr11 [23.1K]

8 0

3 years ago

A 15% tip on a restaurant bill is $3.60. How much is the bill?

ale4655 [162]

Answer:

$3.60.

Step-by-step explanation:

If you want to tip 15%, then the total tip amount would be $2.40 plus half of that again ($1.20), which is $3.60.

7 0

3 years ago

Read 2 more answers

An aquarium with a square base has no top. There is a metal frame. Glass costs 8 dollars/m^2 and the frame costs 7 dollars/m. Th

Irina-Kira [14]

Given that the volume of the aquarium is 20m^3.

Volume = Area of Base x height

Area of Base = Volume / height = 20/h

Given that the aquarium has a square base.

Area of square = l^2

Thus, the length of the base of the aquarium is $\sqrt{area \ of \ base} = \sqrt{ \frac{20}{h} }$

The frame is to cover 8 sides with the length equal to the length of the base and 4 sides with the length of the height.

Thus, the total perimeter of the frame is given by $8\sqrt{\frac{20}{h}}+4h= \sqrt{64\left(\frac{20}{h}\right)}+4h = \sqrt{\frac{1,280}{h}}+4h$

Area of the four side faces of the aquarium is 4 times the length of the base times the height = $4\times\sqrt{ \frac{20}{h} }\times h=\sqrt{16\left(\frac{20}{h}\right)h^2}=\sqrt{320h}$

Total area to be covered by grass is the base and the four side faces and is given by $\frac{20}{h}+\sqrt{320h}$

Cost of the entire metal frame = $7\left(\sqrt{\frac{1,280}{h}}+4h\right)= \sqrt{49\left(\frac{1,280}{h}\right)}+7(4h) = \sqrt{\frac{62,720}{h}}+28h$

Cost of the entire grass = $8\left(\frac{20}{h}+\sqrt{320h}\right)=\frac{160}{h}+\sqrt{64(320h)}=\frac{160}{h}+\sqrt{20,480h$

Therefore, total cost in terms of the height, h, is given by

$C=\sqrt{\frac{62,720}{h}}+28h+\frac{160}{h}+\sqrt{20,480h$

3 0

3 years ago

Find the equation of the line tangent to the function at the given point f(x)=5x^2 at x=10

Svet_ta [14]

f(x) = 5x²

f(10) = 5(10)² = 5(100) = 500

f'(x) = 10x

f'(10) = 10(10) = 100

Now, find the line that passes through (10, 500) and has a slope of 100

y - y₁ = m(x - x₁)

y - 500 = 100(x - 10)

y - 500 = 100x - 1000

y = 100x - 500

8 0

3 years ago

What is the distance between the points P(-5, 4), Q(7, -5)

Nikolay [14]

Answer:

Step-by-step explanation:

Distance between two points is = √(x2 - x1)² + (y2 - y1)²

x1 = -5, y1 = 4; x2 = 7, y2 = -5

|PQ| = √(7 - (-5))² + (-5 - 4)²

|PQ| = √(7 + 5)² + (-9)²

|PQ| = √(12)² + 81

|PQ| = √144 + 81

|PQ| = √225

|PQ| = 15

4 0

3 years ago