Answer:
-<u>One Equation</u>: is set equal to a variable
Example:
y = 2x + 1
x + 3y = -12
You already have y, plug it back into x + 3y = -12
x + 3(2x + 1) = -12
x + 6x + 3 = -12
7x + 3 = -12
(Subtract 3 from each side)
7x = -15
(Divide by 7)
x = - 2.14
-<u>No Equation</u>: is set equal to a variable
Example:
2x + y = 10
4× + 2y = -3
Subtract 2x from each side of 2x + y = 10, you should get y= -2x + 10. Now that you have found y, substitute y into 4x+ 2y = -3.
4x + 2(-2x + 10) = -3
4x + -4x + 20 = -3
(Subtract 20 from each side)
4x + -4x = -23
(Add 4x and -4x)
0 = -23
No Solution
<u>-Both</u><u> </u><u>Equations</u>: are set equal to a variable
Example:
y = x + 5
y = -x + 3
(you already have y so plug it into the other equation to solve for x)
-x + 3 = x + 5
(Add -x on both sides)
3 = 2x + 5
(subtract 5 from both sides)
-2 = 2x
(Divide by 2 on each side)
x = -1
I hope this helped!
This is always ''interesting'' If you see an absolute value, you always need to deal with when it is zero:
(x-4)=0 ===> x=4,
so that now you have to plot 2 functions!
For x<= 4: what's inside the absolute value (x-4) is negative, right?, then let's make it +, by multiplying by -1:
|x-4| = -(x-4)=4-x
Then:
for x<=4, y = -x+4-7 = -x-3
for x=>4, (x-4) is positive, so no changes:
y= x-4-7 = x-11,
Now plot both lines. Pick up some x that are 4 or less, for y = -x-3, and some points that are 4 or greater, for y=x-11
In fact, only two points are necessary to draw a line, right? So if you want to go full speed, choose:
x=4 and x= 3 for y=-x-3
And just x=5 for y=x-11
The reason is that the absolute value is continuous, so x=4 works for both:
x=4===> y=-4-3 = -7
x==4 ====> y = 4-11=-7!
abs() usually have a cusp int he point where it is =0
Hope it helps, despite being this long!
9514 1404 393
Answer:
see attached
Step-by-step explanation:
The attachment shows the ordered pairs (x, f(x)) and their graph.
