Answer: Option A
50 minutes
Step-by-step explanation:
Observe in the diagram that the vertical axis represents the score obtained and the horizontal axis represents the study time.
To find out how many hours the person with a score of 81 studied, locate the point that is at a vertical distance of 81.
Now draw a vertical line from this point to the horizontal axis. Note that the vertical line traced intercepts the vertical axis at x= 50
Then the person who got a score of 81 studied 50 minutes
The answer is the option A
Answer:
22900
Step-by-step explanation:
multiply 350 by 6 and get 2100
subtract 2100 from 25k and get 22900
6. One variable only so pretty straightforward.
length-x+4
width-x
x+x+4=80
2x=76
x=38
x+4=42
answer: length 42cm and width 38cm
7. Another money problem!
n-# of nickels
q-# of quarters
n=3+q
0.05n+0.25q=2.85
Substitution works like a charm!
0.05(3+q)+0.25q=2.85
0.15+0.05q+0.25q=2.85
0.3q=2.7
q=9
n=3+q
n=3+9
n=12
answer: 9 nickels and 12 quarters
8. One variable situation again.
Ann's money-2b+9
Betty's money-b
b+2b+9=60
3b=51
b=17
2b+9=43
answer: Ann has $43 and Betty has $17.
9. # of red m&m's-x+1
# of blue m&m's-x
x+1+x=13
x=6
x+1=7
answer: 6 blue and 7 red m&m's
10. a-number of adult tickets
s-number of student tickets
a+s=785 ----> a=785-s
5a+2s=3280
5(785-s)+2s=3280
-3s=-645
s=215
a+s=785
a+215=785
a=570
answer: 215 children tickets and 570 adult tickets
If the slope of AB = CD and BC = AD it's a parallelogram:
Slope of AB = 6+1 / -9+5 = -7/4
CD = -2-5 / 3+1 = -74
These are equal.
BC = 5-6 / -1 +9 = -1/8
AD = -2 +1 / 3+5 = -1/8
These are also equal so it is a parallelogram.
Now to find if the diagonals are perpendicular find the slope of the perpensicular points:
AC = 5 +1 / -1 +5 = 6/4 = 3/2
BD = 6+2 / -9 -3 = 8/-12 = -2/3
Because BD is the reciprocal of AC, this means they are perpendicular.
And because AB is not perpendicular to AD ( AB and AD are not reciprocals) it is a rhombus.
