Answer:
In a system, the substitution method is one of the 3 main ways to solve a system and can be very efficient at times.
<u>Skills needed: Systems, Algebra</u>
Step-by-step explanation:
1) Let's say we are given two equations below:
We can use substitution here by substituting in for 
in the second equation. This means we put in 
for in the 2nd equation so we only have 
variables in the equation, allowing us to solve for .
2) Solving it out:
We essentially substitute in that value as seen in step 1. Steps 2 and 3 are just simplifying the left side and allowing for us to solve. Step 4 is where we divide by -16 on both sides to solve for x. Step 5 and 6 show us solving for y using the value for x. We get 
6.375 is greater than 6.333
Step-by-step explanation:
If x is the volume of the first tank, and y is the volume of the second tank, then:
x + y = 55
x = 2y + 4
Solve the system of equations using either substitution or elimination. Using substitution:
2y + 4 + y = 55
3y + 4 = 55
3y = 51
y = 17
Solve for x using either equation.
x + 17 = 55
x = 38
The first tank holds 38 gallons, and the second tank holds 17 gallons.
Given the functions
(a) f(x) = x³ + 5x² + x
(b) f(x) = x² + x
(c) f(x) = -x
Function (a)
f(-x) = (-x)³ + 5(-x)² + (-x)
= -x³ + 5x² - x
= -(x³ - 5x² + x)
The function is neither even nor odd.
Function (b)
f(-x) = (-x)² + (-x)
= -(-x² + x)
The function is neither even nor odd.
Function (c)
f(-x) = -(-x)
= x
= -f(x)
Because f(-x) = -f(x) the function is odd.
Answer: f(x) = -x is an odd function.
