Answer:
8
Step-by-step explanation:
Let's just call the number x for simplicity.
So, 7x is 8 less than x².
Putting this into an equation would look like this
x² - 8 = 7x
It looks like we'll have to factor this to solve. Before we do that we need to move the 7x to the left side so that everything is together.
x² - 7x -8 = 0
Now, we can proceed. To factor we first need to find the factors of -8.
The factors of -8 are
-2 ⋅ 4, -4 ⋅ 2, -1 ⋅ 8, 1 ⋅ -8.
We need to find the pair of factors that adds up to -7. The only ones that do are -1 and 8.
So now that we have these we can create a pair of binomials using them. This will give us the factored form of this equation.
( x + 1 ) ( x - 8 )
To find the solutions we will have to set them to 0 and solve each of these binomials individually.
x - 1 = 0
x = 1
So, one of the solutions is 1. It's not the one we want, since it's positive.
x - 8 = 0
x = 8
This is the one we want since it is positive.
Answer:
(P, Q) = (-75, 57)
Step-by-step explanation:
The equation will have infinitely many solutions when it is a tautology.
Subtract the right side from the equation:
Px +57 -(-75x +Q) = 0
x(P+75) +(57 -Q) = 0
This will be a tautology (0=0) when ...
P+75 = 0
P = -75
and
57-Q = 0
57 = Q
_____
These values in the original equation make it ...
-75x +57 = -75x +57 . . . . . a tautology, always true
30+5y_>4x
5y_>4x-30
The answer is: y_>(4/5)x-6
Answer:
Option A
Step-by-step explanation:
Given:
- a. 3x-5= 3x + 5
- b. 3x-5= 3x - 5
- c. 3x - 5 = 2x+5
- d. 3x-5 = 2x + 10
To find:
- Which one of the linear equations have no solution.
Solution:
a) 3x-5= 3x + 5
Add 5 to both sides
3x-5= 3x + 5
3x - 5 + 5 = 3x + 5 + 5
Simplify
(Add the numbers)
3x - 5 + 5 = 3x + 5 + 5
3x = 3x + 5 + 5
(Add the numbers)
3x = 3x + 5 + 5
3x = 3x + 10
Subtract 3x from both sides
3x = 3x + 10
3x - 3x = 3x + 10 - 3
Simplify
(Combine like terms)
3x -3x = 3x + 10 - 3
0 = 3x + 10 - 3
(Combine like terms)
0 = 3x + 10 - 3
0 = 10
The input is a contradiction: it has no solutions
b) 3x-5= 3x - 5
Since both sides equal, there are infinitely many solutions.
c) 3x - 5 = 2x+5
Add 5 to both sides
3x = 2x + 5 + 5
Simplify 2x + 5 + 5 to 2x + 10
3x = 2x + 10
Subtract 2x from both sides
3x - 2x = 10
Simplify 3x - 2x to x.
x = 10
d) 3x-5 = 2x + 10
Add 5 to both sides
3x = 2x + 10 + 5
Simplify 2x + 10 + 5 to 2x + 15
3x = 2x + 15
Subtract 2x from both sides
3x - 2x = 15
Simplify 3x -2x to x.
x = 15
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Answer:
As you can see all c and d both have solutions, eliminating them as options. Option B has infinite solutions leaving Option A which has no solutions.
Therefore, <u><em>Option A</em></u> is the linear equation that has no solution.
