21x -15 + 5 = 10x - 5
21x -5 = 10x
11x = 5
x = 5/11
Answer:
<em>(a) x=2, y=-1</em>
<em>(b) x=2, y=2</em>
<em>(c)</em> 
<em>(d) x=-2, y=-7</em>
Step-by-step explanation:
<u>Cramer's Rule</u>
It's a predetermined sequence of steps to solve a system of equations. It's a preferred technique to be implemented in automatic digital solutions because it's easy to structure and generalize.
It uses the concept of determinants, as explained below. Suppose we have a 2x2 system of equations like:

We call the determinant of the system

We also define:

And

The solution for x and y is


(a) The system to solve is

Calculating:





The solution is x=2, y=-1
(b) The system to solve is

Calculating:





The solution is x=2, y=2
(c) The system to solve is

Calculating:





The solution is

(d) The system to solve is

Calculating:





The solution is x=-2, y=-7
Answer:
120 pi
Step-by-step explanation:
a. 1/3pi(6)^2(10)
just plug them into the calculator using pi.
b. pi is more accurate because you aren't round to 3.14. If you use 3.14 your answer will be rounded and not an exact number.
Answer: The sum of 75.2+(57.376+24.8) is 157.376.
Explanation:
The commutative property of addition states that,

The associative property of addition states that,

The given expression is 75.2+(57.376+24.8).
First use commutative property of addition in the parenthesis.

Now use associative property of addition.

Now simplify the expression,


Therefore, the sum of 75.2+(57.376+24.8) is 157.376.
Answer:

Step-by-step explanation:
Given that,
Mass of a certain material, m = 71 pounds
Since, 1 ton = 2000 pounds
71 pounds = 0.0355 ton
Volume of the material, V = 2.5 gallons
Since, 1 m³ = 264.172 gallon
2.5 gallon = (2.5/264.172 ) m³
Density,
