Focus on the regression line. Notice how (0,90) and (1,75) are on this line. Compute the slope of the line through those points
Use the slope formula
m = (y2-y1)/(x2-x1)
m = (75-90)/(1-0)
m = -15/1
m = -15
So Matthew's balance is decreasing by approximately 15 dollars each month. The negative slope means "decrease". This is shown by the fact that the line goes downhill as you move from left to right.
Answer: decreases by $15 each month
Answer:
x = 13.5
Step-by-step explanation:
direct variation
y = kx
substitute x and y to find k
8 = k*6
divide by 6
8/6 =k
4/3 = k
y = 4/3 x
now put in y =18
18 = 4/3 x
multiply by 3/4
18 * 3/4 = 3/4 * 4/3 x
54/4 = x
change to a decimal
13.5 =x
Answer: y-7 = 4(x+3), choice B
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Point slope form is generally
y-y1 = m(x-x1)
we have m as the slope and (x1,y1) as the point this line goes through. In this case,
m = 4
(x1,y1) = (-3,7) so x1 = -3 and y1 = 7
So,
y-y1 = m(x-x1)
y - 7 = 4(x - (-3))
y - 7 = 4(x + 3)
which is why choice B is the answer
Answer:
from that passage AB+BD=AD ; -4x+50+2x+4=2x+46 so -2x+54=2x+46 ; x=2.
AC=AB+BC ; AB=-4x+50=-4(2)+50=42
the total lengths is AD=2x+46=50
Therefore AC is more than 42 and less than 50 ; you can answer b,c,g
Same as last time:
d^2=(x2-x1)^2+(y2-y1)^2
d^2=(6--1)^2+(-2-4)^2
d^2=7^2+(-6)^2
d^2=49+36
d^2=85
d=√85 (85=5*7 and both 5 and 7 are prime so √85 cannot be simplified any further)
The exact distance is √85 units.
