Answer:
6(1-5m) = 6
−
30
m
3(4+3r) = 12
+
9
r
3(6r+8) = 18
r
+
24
4(811+ 1+2) = 3256
-(-2-n) 7) = 14
+
7
n
-6(7k+11) = −
42
k
−
66
-3(71+1) = −
216
-6(1 +116) = −
702
-10(a - 5) = −
10
a
+
50
-3(1 + 2v) = −
3
−
6
v
-4(3r+2) = −
12
r
−
8
(3 - 76)-2 = −
75
(-2018x+20) = −
2018
x
+
20
(7 + 190)-15 = 182
(x + 1)14 = 14
x
+
14
1.25 hours for each lawn. 1.25 x 7 = 8.75.
Answer:
The percentage of students who scored below 620 is 93.32%.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:

Percentage of students who scored below 620:
This is the pvalue of Z when X = 620. So



has a pvalue of 0.9332
The percentage of students who scored below 620 is 93.32%.
ANSWER

EXPLANATION
The quadratic equation is:

Group variable terms:

Add the square of half, the coefficient of y to both sides.


The LHS us now a perfect square trinomial:

Take square root:


The first choice is correct.