Answer:
x =
or 0.706
or 1.735
Step-by-step explanation:
5x + 2y=7 ----->(eq 1)
- 2x + 6y=9 ----->(eq 2)
Multiply (eq 1) with 3
3×(5x + 2y) = 3×7
15x + 6y = 21 ----->(eq 3)
substract (eq 3) from (eq 2)
- 2x + 6y - (15x + 6y) = 9-21
- 2x + 6y - 15x - 6y = 9-21
- 2x - 15x + 6y - 6y = 9-21
-17x = -12
x = -12 ÷ -17
x = 
put x =
in (eq 1)






Step-by-step explanation:
a1 = 27
r = -9/27 = -⅓
the formula :
an = a1. r^(n-1)
= 27. (-⅓)^(n-1)
= 3³(-3`¹)^(n-1)
= 3³(-3)^(1-n)
You multiply 0.4 by 4.2 and that equals 1.68 so sumeet uses 1.68 gallons of gas in 4.2 hours.
ANSWER
A. 22 in
EXPLANATION
The volume of a cone is calculated using the formula:

It was given that: the volume is 2,279.64 in³
The height of the cylinder is also given as: h=18 in.
We substitute, the given values into the formula to get:




We take positive square root to get;


Therefore the diameter is 2(11) which is equal to 22 inches.
Answer: D . 
Step-by-step explanation:
Given : Jenny studied the characteristics of two species of bacteria. The number of bacteria of species A, A(t), after t hours is represented by the function,

The number of bacteria of species B, B(t), after t hours is represented by the function, 
Then, the difference in the number of bacteria, N(t), of both the species after t hours will be :-

Hence, the correct answer should be : D . 