Solving Simultaneous Equations

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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