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 
Answer:
Step-by-step explanation:
The equation of a straight line can be represented in the slope intercept form as
y = mx + c
Where
m = slope = (change in the value of y in the y axis) / (change in the value of x in the x axis)
The equation of the given line is
7x+4y=3
4y = - 7x + 3
y = -7x/4 + 3/4
Comparing with the slope intercept form, slope = -7/4
If the line passing through the given point is perpendicular to the given line, it means that its slope is the negative reciprocal of the slope of the given line.
Therefore, the slope of the line passing through (6,-9) is 4/7
To determine the intercept, we would substitute m = 4/7, x = 6 and y = -9 into y = mx + c. It becomes
- 9 = 4/7×6 + c = 24/7 + c
c = - 9 - 24/7 = -87/7
The equation becomes
y = 4x/7 - 87/7
ANSWER
The radius is 25 inches
EXPLANATION
From the diagram, the radius of the circle is AC.
From the Pythagoras Theorem,


Simplify

Take positive square root,


Hence the radius is 25 inches
Answer: The answer is C
Step-by-step explanation:
The answer is Day 3. The blue bar for day 3 is the tallest, which means that was the highest amount.