You’re answer should be 9-7 hope this helped
Distribute the two to each of the values in the parentheses.
-4 +6a-10= 1-1a
Then move like terms to the same side to simplify.
6a+1a=1+10+4
7a=15
a=15/7
Coefficient of variation is the ratio of the standard deviation to the mean (average)
Coefficient of variation = (standard deviation/mean) × 100

×

=
19 is prime meaning that only 1 and itself can multiply to get that number (excluding decimals and fractions)
so the answer would be 1 times 19
or if you want to multiply by a fraction to divide you could do
38 times 1/2=19
X - 5 = x^2
i) 0 - 5 = -5^2 = 25
ii) 4 - 5 = -1^2 = 1
iii) -4 - 5 = -9^2 = 81