How do you evaluate: To evaluate an algebraic expression, you have to substitute a number for each variable and perform the arithmetic operations. In the example above, the variable x is equal to 6 since 6 + 6 = 12. If we know the value of our variables, we can replace the variables with their values and then evaluate the expression.
Complete Question: Which of the following is an example of the difference of two squares?
A x² − 9
B x³ − 9
C (x + 9)²
D (x − 9)²
Answer:
A.
.
Step-by-step explanation:
An easy way to spot an expression that is a difference of two squares is to note that the first term and the second term in the expression are both perfect squares. Both terms usually have the negative sign between them.
Thus, difference of two squares takes the following form:
.
a² and b² are perfect squares. Expanding
will give us
.
Therefore, an example of the difference of two squares, from the given options, is
.
can be factorised as
.
Let the two numbers be x and y, then,
xy = -12 . . . (1)
x + y = -10 . . . (2)
From (2), x = -10 - y . . . (3)
Putting (3) into (1), gives
(-10 - y)y = -12
-10y - y^2 = -12
y^2 + 10y - 12 = 0

Therefore, the two numbers are

and
Answer:
The answer is (1,2) (4,4) (3,7)
Step-by-step explanation:
Y=3x-13 x=-2y-11 that’s elimination answers for both