The given equation is: 
To find the line perpendicular to it, we interchange coefficients and switch the signs of one coefficient.
The equation to a line perpendicular to it is:
$ 2y-x=c$
where, $c$ is some constant we have determine using the condition given.
It passes through $(2,-1)$
Put the point in our equation:
$2(-1)-(2)=c$
$c=-2-2$
$c=-4$
The final equation is:
$\boxed{ 2y-x=-4}$
I’m learning this too.. so what you do it see what will the number he if it was a while line so to find that out you will add 7+7 and get 14 so that’s the whole
So 7 x 7 will equal 49 and 49 x 3.14 will give you 153.86 as the answer
You would get 89/21 and then for a mixed number 4& 5/21
Answer:
22) y=1/4x-3/4
23) y=-1/3x-9
Step-by-step explanation:
22 ) Using the rise/run strategy, we can find the slope. From (-1,-1) you go up 1 unit to reach the same level as (3,0), and go right 4 to reach (3,0). This means your rise/run is 1/4, which is also your slope. Now to find the y-intercept, we can use the equation format y=mx+b. m is your slope, which we have, and b is the y intercept. With y and x, we can substitute in a point we already know, for example (-1,-1) as (x,y). When everything we know is substituted in, we get -1=(1/4)(-1)+b. According to PEMDAS, we should now multiply 1/4 and -1 to get (-1/4). Now our equation is -1=-1/4+b. To isolate B, we need to add 1/4 on both sides. As a result, you'll get -3/4. Your y intercept is -3/4. Thus, the final equation is y=1/4x-3/4.
23) This question is a lot more straight forward than question 22. In this question, you're already given everything in the equation to substitute everything in. Like I said before, the format for a linear equation is y=mx+b where m is your slope and b is your y intercept. This question already gives you both the slope and y intercept, so you can just fill it in. (m = -1/3, b= -9) Thus, you'll get y=-1/3x-9.
Answer:
<em>20 boys </em>
Step-by-step explanation:
b = 2g
100% - 20% = 80%
80% ÷ 2 = 40% = 0.4
0.4g = 4 ⇒ g = 4 ÷ 0.4 = 10
b = 2 × 10 = 20
There are 10girls and <em>20 boys</em> study in the class.
