Question

Date :
Activity 3
Complete the following activity, to solve the
simultaneous equations 3x +2y = 6 and 2x + 4y = 12
by Cramer's rule :
6 2
3 2
D= = 8, DX
2 41
32
1
12 4
13
6
D
2 12
and y=[
X=
​

Answer 1

Step-by-step explanation:

$3x + 2y = 6 \\ 3x = 6 - 2y \\ \: \: {x = 6 - 2y \div 3} \: eq \: 1 \\ \\ 2x + 4y = 12 \\ 2(6 - 2y \div 3) + 4y = 12 \\ 12 - 4y \div 3 + 4y = 12 \\ 12 - 4y + 12y \div 3 = 12 \\ 12 - 4y + 12y = 12 \times 3 \\ 12 + 8y = 36 \\ 8y = 36 - 12 \\ 8y = 24 \\ y = 24 \div 8 \\ y = 3 \\ \: \: (put \: y = 3 \: in \: eq \: 1 \ x = 6 - 2y \div 3) \\ \\ x = 6 - 2y \div 3 \\ x = 6 - 2(3) \div 3 \\ x = 6 - 2 \\ x = 4 \: \: \: \: \: \\ x = 4\: \: and \: \: \: y = 3 \: \: \: ans.$