1. Work out the values of N and M

(1) 8m+ 4n = 104

(2) 8m + 2n = 134

2n = -30
n = -15

(1)
8m + 4(-15) = 104
8m - 60 = 104
8m = 164
m = 20.5

(2)
8(20.5) + 2(-15) = 134
164 - 30 = 104

N = -15
M = 20.5

2. Work out the values of A and B

(1) 3a + 4b = 14
(2) 4a + 2b = 2

(2 x2) 8a + 4b = 4
(1) 3a + 4b = 14
5a = -10
a = -2

(1)
3(-2) + 4b = 14
-6 + 4b = 14
4b = 20
b = 5

(2)
4(-2) + 2(5) = 2
-8 + 10 = 2

A = -2
B = 5

3. Work out the values of X and Y
(1) 5x + 2y = 26
(2) 8x - 4y = 20

(! x2) 10x + 4y = 52
(2) 8x - 4y = 20
[Add Equations Together as one is -4 and the other +4]
18x = 72
x = 4

(1)
5(4) + 2y = 26
20 +2y = 26
2y = 6
y = 3

(2)
8(4) - 4(3) = 20
32 - 12 = 20
x = 4
y = 3

	Created by jackhutcheson almost 9 years ago

GCSE Maths Note on Solving Simultaneous Equations, created by jackhutcheson on 09/02/2016.