Write an equation to represent the number puzzle. Use x as the
variable. Then find the solution using guess-check-and-improve.
7 added to the square of a number is equal to 7 times the number,
minus 5. What is the number? (There are two solutions.)
a. 7 + x = 7x − 5, 2 c. 7 + x2 = 7x − 5, 2 or 3
b. 7 + x2 = 7x − 5, 3 or 4 d. 7 + x2 = 7x − 5, 4 or 5

Given that,

7 added to the square of a number is equal to 7 times the number,  minus 5

Let "x" be the unknown number

From given,

7 added to square of x = 7 times the x minus, 5

Solve the above equation

Split the middle term

We have two solutions

x - 3 = 0

x = 3

And

x - 4 = 0

x = 4

Thus number is 3 or 4

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value