Answer:
Value of x is used to consider unknown value. The letter “x” is commonly used in algebra to indicate an unknown value. It is referred to as a “variable” or, in some cases, a “unknown.” In x + 2 = 7, x is a variable. ... A variable need not be “x,” but might be “y,” "w," or any other letter, name, or symbol.
The most important part of this question is understanding the words of the problem. The trick lies in the words of the problem. Once the web of words is simplified, the problem becomes very easy. The main thing is converting the words into numbers.
Let us assume the unknown number = x
Then from the question we get
(x/4) = (x/5) + 1
(x/4) - (x/5) = 1
(5x - 4x)/20 = 1
x/20 = 1
x = 20
So the unknown number is 20
c) opposite edges of a computer screen
D - -x^2 + 3x + 7
To find this, first write out the equation:
(3x + 1) - (x^2 - 6)
Distribute the negative into x^2 and -6 so you're equation now looks like this:
3 x + 1 - x^2 + 6
Combine like terms and arrange the equation into ax^2 + bx + c to get the final answer of:
-x^2 + 3x + 7
Hope this helps!