Answer:
Solving systems of equations with 3 variables is very similar to how we solve systems with two variables. When we had two variables we reduced the system down
to one with only one variable (by substitution or addition). With three variables
we will reduce the system down to one with two variables (usually by addition),
which we can then solve by either addition or substitution.
To reduce from three variables down to two it is very important to keep the work
organized. We will use addition with two equations to eliminate one variable.
This new equation we will call (A). Then we will use a different pair of equations
and use addition to eliminate the same variable. This second new equation we
will call (B). Once we have done this we will have two equations (A) and (B)
with the same two variables that we can solve using either method. This is shown
in the following examples.
Example 1.
3x +2y − z = − 1
− 2x − 2y +3z = 5 We will eliminate y using two different pairs of equations
5x +2y − z = 3
Step-by-step explanation:
Answer:
0.25
Step-by-step explanation:
Average means 
According to the formula, each student in Mr. Goldwasser's class read
books on average, and each student in Mr. Welch's class read
books on average.
Therefore, the answer will be
8x + 2x
Plug the variable in.
8×6 + 2×6
48+12 = 60
Answer:
301.6 ft³
Step-by-step explanation:
The volume (V) of a cone is calculated using the formula
V = 
× area of base × perpendicular height (h)
h can be calculated by using Pythagoras' identity in the right triangle
with hypotenuse = 10 and legs 6 and h, thus
h² + 6² = 10²
h² + 36 = 100 ( subtract 36 from both sides )
h² = 64 ( take the square root of both sides )
h = 
= 8
Hence
V = × π × 6² × 8
= × 288π = 
≈ 301.6
1 ) the formula used to calculate the simple interest is
I = Ci*n, f his formula you obtain n , that is the time in years n = I/ Ci, where c is the initial capital, i is the earned interest , and i is he rate of interest,
n = 120/600 (0,025) = 120 / 15 = 8 , at 8 years, you will obtain $ 120 of INTEREST
