The subtraction theorem states that for all real numbers,

and

,

.
(To subtract, we can add the inverse.)
Thus, we can have the these two equivalent expressions.
Answer:
a = 9
Step-by-step explanation:
Simplifying
8.1 = 0.9a
Solving
8.1 = 0.9a
Solving for variable 'a'.
Move all terms containing a to the left, all other terms to the right.
Add '-0.9a' to each side of the equation.
8.1 + -0.9a = 0.9a + -0.9a
Combine like terms: 0.9a + -0.9a = 0.0
8.1 + -0.9a = 0.0
Add '-8.1' to each side of the equation.
8.1 + -8.1 + -0.9a = 0.0 + -8.1
Combine like terms: 8.1 + -8.1 = 0.0
0.0 + -0.9a = 0.0 + -8.1
-0.9a = 0.0 + -8.1
Combine like terms: 0.0 + -8.1 = -8.1
-0.9a = -8.1
Divide each side by '-0.9'.
a = 9
Simplifying
a = 9
1/2 fraction of whole carton was used for each serving
If a binomial x-a is a factor of a polynomial p(x), then p(a)=0.
x+2 is a factor of p(x)=x³-6x²+kx+10, so p(-2)=0.
Answer:
Q1) (x+7)² = 9
x = -10, -4
Q2) (x-8)² = 144
x = -4, 20
Q3) (x-1)² = 81
x = -8, 10
Step-by-step explanation:
Q1) x² + 14x + 49 = 9
x² + 2(x)(7) + 7² = 9
(x + 7)² = 9
x + 7 = +/- sqrt(9)
x + 7 = 3
x = -4
x + 7 = -3
x = -10
Q2) x² - 16x + 64 = 144
x² - 2(x)(8) + 8² = 144
(x - 8)² = 144
x - 8 = +/- sqrt(144)
x - 8 = 12
x = 20
x - 8 = -12
x = -4
Q3) x² - 2x + 1 = 81
x² - 2(x)(1) + 1² = 81
(x - 1)² = 81
x - 1 =+/- sqrt(81)
x - 1 = 9
x = 10
x - 1 = -9
x = -8