1. since the equations equal each other
2x+19=x+7
-x -x
x+19=7
-19 -19
x= -12
sub into y= x+7
y= -12+7
y= -5
2. x+2y=-7
<span>x+y+23=0
i don't know what the second equation is equal to, i'll assume 0
2y=x-7
y=1/2x-7/2
sub this into x+y+23=0
x+1/2x-7/2+23=0
3/2x+39/2=0
-39/2 -39/2
3/2x= -39/2
x=-39/2 / 3/2
x= -13
sub into y=1/2x-7/2
y=1/2(-13)-7/2
y= -10
3. </span>x+5y=2
<span>x=-4y+5
</span>sub x=-4y+5 into x+5y=2
-4y+5+5y=2
y+5=2
-5 -5
y= -3
sub y =-3 into x =-4y+5
x=-4(-3)+5
x= 17
4. 3x+y=9
<span>y=-5x+9
</span>sub -5x+9 into 3x+y=9
3x+(-5x+9)=9
3x-5x+9=9
-2x+9=9
-9 -9
-2x=0
x=0
sub into y=-5x+9
y=-5(0)+9
y=9
The square root of a a negative integer is imaginary.
It would still be a negative under a square root if you multiplied it by 2, therefor it will still be imaginary, or I’m assuming as your book calls it, undefined.
2•(sqrt-1) = 2sqrt-1
If you add a number to -1 itself, specifically 1 or greater it will become a positive number or 0 assuming you just add 1. In that case it would be defined.
-1 + 1 = 0
-1 + 2 = 1
If you add a number to the entire thing “sqrt-1” it will not be defined.
(sqrt-1) + 1 = 1+ (sqrt-1)
If you subtract a number it will still have a negative under a square root, meaning it would be undefined.
(sqrt-1) + 1 = 1 + (sqrt-1)
however if you subtract a negative number from -1 itself, you end up getting a positive number or zero. (Subtracting a negative number is adding because the negative signs cancel out).
-1 - -1 = 0
-1 - -2 = 1
If you squared it you would get -1, which is defined
sqrt-1 • sqrt-1 = -1
and if you cubed it, you would get a negative under a square root again, therefor it would be undefined.
sqrt-1 • sqrt-1 • sqrt-1 = -1 • sqrt-1 = -1(sqrt-1)
Sorry if this answer is confusing, I don’t have a scientific keyboard, I’ll get one soon.
C) closest to 2/5.
2/3 is bigger than half 2/10 would be like less than 1/4
Answer:
The scatter diagram that contains the correlation coefficient closest to r = 1 is the first one shown in the attached images.
Step-by-step explanation:
The correlation coefficient "r" measures how much two variables x and y are related. When the variables are highly related, the value of r is closer to one and the points contained in the scatter diagrams are assimilated more and more to a line. When the value of r is positive the relation is crescent and therefore the slope of the line drawn by the points in the diagram has a positive slope
Therefore, to answer this question, one must search among the attached images for the dispersion diagram in which the points resemble a straight line with a positive slope.
The scatter diagram that meets the requirements mentioned is the first one that appears in the attached images
Answer:
8 out of 84: 90% decrease
200 out of 238: 16% decrease
Step-by-step explanation:
To find a percent decrease, you first subtract the end number by the initial number. This gives you the change.
ex. 84-8=76
Now you divide the change by the initial number. You'll get a decimal.
ex. 76/84=0.904...
Multiply the decimal times 100, or move the decimal to the right twice.
ex. 0.904... -> 90.4...
Now round to the nearest ones place
ex. 90.4 -> 90%
