Answer60
Step-by-step explanation:
Answer:
-9.85
Step-by-step explanation:
-15.5 - 4.2 = -19.7
Negatives work like positives
19.7 / 2 = 9.85
Turn that into a negative
-9.85
Answer:
See solutions below
Step-by-step explanation:
For what values of X are the statements below true
A. 1x>x+1
x >x+1
x-x>1
0x > 1
x > 1/0
X >∞
B) |1-x|>3
The fucntion can both be positive and negative
For the negative function
-(1-x) > 3
-1+x > 3
x > 3+1
x > 4
For the positive function
1-x > 3
-x > 3 - 1
-x > 2
x < -2
Hence the required solutions are x > 4 and x < -2
c) For the equation
|x-15| < 0
-(x - 15) < 0
-x + 15 < 0
-x < -15
x > 15
Also x-15 < 0
x < 0+15
x < 15
Hence the required solution is x > 15 and x < 15
These problems are called systems of equations. Basically you have two linear equations and you need to find the values for x and y. In other words, all these equation are lines and our answer will be the exact point that the pair of lines intersect. For example, if we get x=1 and y=2 the lines will intersect at point (1,2). Now that you have some background knowledge here comes the tricks and tactics kid.
We know that we can solve one variable equation easily. For example...
x+1=2
x=1 obviously
Cause we have two variables x and y it is not possible to find a solution. For example, in the equation x+y=10, x=1 when y=9 and x=2 when y=8. There is not correct answer.
So what can we do? We have to make a two variable equation into a one variable equation.
There are two ways to do this: substitution and elimination. I will create a sample problem and then solve it using both methods.
x+y=2
2y-y=1
3)
-3x-5y=-7 -----> -12x-20y=-28
-4x-3y=-2 ------> -12x-9y=-6
-12x-20y=-28
-(-12x-9y=-6)
---------------------
-11y=-22
y=2
-3x-5(2)=-7
-3x=3
x=-1
4) 8x+4y=12 ---> 24x+12y=36
7x+3y=10 ---> 28x+12y=40
28x+12y=40
-(24x+12y=36)
---------------------
4x=4
x=1
8(1)+4y=12
4y=4
y=1
5) 4x+3y=-7
-2x-5y=7 ----> -4x-10y=14
4x+3y=-7
+(-4x-10y=14)
-------------------
-7y=7
y=-1
4x+3(-1)=-7
4x=-4
x=-1
6) 8x-3y=-9 ---> 32x-12y=-36
5x+4y=12 ---> 15x+12y=36
32x-12y=-36
+(15x+12y=36)
--------------------
47x=0
x=0
8(0)-3y=-9
-3y=-9
y=3
7)-3x+5y=-2
2x-2y=1 ---> x-y=1/2 ----> x=y+1/2
-3(y+1/2)+5y=-2
-3y-1.5+5y=-2
2y=-0.5
y=0.25
2x-2(0.25)=1
2x=1.5
x=0.75
