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4. Find k in each case, if x=2,y=1 is a solution of the equation: a) 3x+2y=k b)2x - ky =6 c)x/4 +y/3 =5k​

1 Answer

3 votes

Answer:

k = 8, -2 and 1/6

Explanation:

To get k, represent x with 2 and y with 1 in all equations

a) 3x + 2y = k

3(2) + 2(1) = k

6 + 2 = k

k = 8

b) 2x - ky = 6

2(2) - k(1) = 6

4 - k = 6

4 - 6 = k

k = -2

c) x + y = 5k

4 3

2 + 1 = 5k

4 3

Using the lcm of 4 and 3 to add the fractions

6 + 4 = 5k

12

10 = 5k

12

cross multiply

5k × 12 = 10

60k = 10

k = 10

60

k = 1/6

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