5.6 x 2.1 x 6.6 = 77.616 2 significant figures would be 78 cm³ 2 decimal places would be 77.62 cm³
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
To factor,
<h2>
[[[</h2>
1) First multiply coefficient of a² and constant no,
That is,
3×(-42)=-126
Since the<u> resultant no is negative</u>, you should find two such factors of 126 <u>which</u> <u>will give us the coefficient of a (=11)</u> on subracting those factors.
2) Find the factor
126=2×3×3×7
=18×7
18 and 17 are factors of 126
Also,18-7 =11.
So they are required factors for factoring,
<h2>
]]]</h2>
Once you have understood above steps you can solve on your own. All you need to do is split 11 into factors ,take common terms and you will get answer.
<u>Answer:</u>
3a²+11a-42
=3a²+(18-7)a -42
=3a²+18a-7a-42
=3a(a+6) -7(a+6)
=(a+6)(3a-7)
Answer:
(13+x)cm
Step-by-step explanation:
Given data
Length of sides
1cm, 5cm, 7cm
Since the shape is four-sided and the fourth side is not given, let the fourth side be x
so
The perimeter of the polygon is
P= 1+5+7+x
P= 13+x
Hence the perimeter of the polygon is
P= (13+x)cm