Answer:
The first option is not a direct variation
Step-by-step explanation:
When we talk of a direct variation, as one value increases, the other value increases too
Or as one value decreases, the other value decreases
A direct variation is of the form;
y = kx
k = y/x
where k is the coefficient of variation that must be a constant value all through the set of values
The values we are comparing here are the x and y values
So
let us take a look at the options;
The first option is not a direct variation
For the first option, the rate of increase is not constant;
2/6 = 1/3 , 8/12 = 2/3 , 14/18 = 7/9
for the second;
the ratio is 1 to 1
for the third;
3/6 = 1/2 ; 6/12 = 1/2; 9/18 = 1/2
for the fourth;
2/6 = 1/3, 4/12 = 1/3 , 6/18 = 1/3
Step-by-step explanation:
We have to get one positive 7y so,
4x-7y=5
9x-7y=-15
multiply anyone of the equation by -1. I choose the first one so,
4x+7y=-5
9x-7y=-15
we can now cancel the y's so the equation will be left with
-4x=-5
9x=-15
add the equations
5x=-20
divide by 5 n u get
x=-4
now plug in the x value in any one of the
equations
I choose the first one so,
4(-4)-7y=5
-16-7y=5
add 16 to both sides
-7y=21
divide by -7
y=-3.
finally check.
Amp is the number in front of sine so its 1/2 aka D :)
A = ((6 + 7 + 6) . 8)/2
A = 19 . 4
A = 76
