Question

If 3x + 4y = 10 and -6x +by = -20 then b =

Answer 1

Answer:

b = (-8)

Step-by-step explanation:

We have,

3x + 4y = 10 ------ 1

-6x + by = (-20) ------- 2

Multiplying equation 1 with 2

3x + 4y = 10 (×2)

6x + 8y = 20 ------ 3

Adding eq.2 and eq.3 we get,

-6x + by + 6x + 8y = (-20) + 20

6x - 6x + 8y + by = 20 - 20

0 + 8y + by = 0

y(8 + b) = 0

b + 8 = 0/y

b + 8 = 0

b = (-8)

Hence,

b = (-8)

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