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3 years ago

2x-y²=1 3x+y=4 Heelp...

1 answer:

6 0

So first we solve for y in second equation
3x+y=4
y=4-3x
sub for y in first equiton
2x-(4-3x)^2=1
2x-(16-12x-12x+9x^2)=1
2x-(16-24x+9x^2)=1
2x-16+24x-9x^2=1
-9x^2+26x-16=1
times -1 both sides
9x^2-26x+16=-1
add 1 to both sides
9x^2-26x+17=0
factor
(x-1)(9x-17)=0
set each to zero
x-1=0
x=1

9x-17=0
9x=17
x=17/9

so sub back to find y
y=4-3x
y=4-3(1)
y=4-3
y=1
(1,1)

y=4-3x
y=4-3(17/9)
y=4-17/3
y=12/3-17/3
y=-5/3
(17/9,-5/3)

the 2 intersection points are
(1,1) and $( \frac{17}{9} , \frac{-5}{3} )$

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How do I solve this?

Ivenika [448]

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7 0

3 years ago

Y is directly proportional to the square of x.

RUDIKE [14]

Answer:

The value of y is 847 for x=11

Step-by-step explanation:

It is given that y is directly proportional to the square of x

This can be written mathematically as:

$y \propto x^2$

Removing the proportionality symbol introduces a proportionality constant in the equation which is denoted by k

$y = kx^2$

Given that "When x is 5, y is 175"

$175 = k (5)^2\\175 = k*25\\k = \frac{175}{25}\\k = 7$

Putting the value of k

$y = 7x^2$

Now putting x = 11

$y = 7(11)^2\\y = 7 * 121\\y = 847$

Hence,

The value of y is 847 for x=11

5 0

3 years ago

There are 812,000 gallons of water in an Olympic training center’s pool. Express this number in scientific notation

DerKrebs [107]

8.12 ×10^5 is the answer

7 0

3 years ago

Read 2 more answers

Graph the line whose y-intercept is -7 and whose x-intercept is 1

vesna_86 [32]

Answer:

$y=7x -7$

Step-by-step explanation:

We are given two points, the y - intercept and the x - intercept.

The y - intercept being: ( 0, -7 )

The x - intercept being: ( 1, 0 )

The equation of a line in slope - intercept form is:

y = mx + b, where m is the slope and b is the y - intercept.

We already have the y - intercept. So far we have:

y = mx - 7

What we're missing is the slope.

To find the slope, we can use this formula:

$\frac{y_{2}-y_{1} }{x_{2}-x_{1}}$ , where $x_{2}$ and $x_{1}$ are the x - coordinates of both points and $y_{2}$ and $x_{1}$ are the y - coordinates of both points.