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2 years ago

What is the value of 9a + 6b?

Mathematics

2 answers:

Svetlanka [38]2 years ago

6 0

i) 3a+2b=9 /*3

9a+6b=27

ii) 8x+6y=60 /: 2

4x+3y=30

Pachacha [2.7K]2 years ago

3 0

Answer:

Step-by-step explanation:

9a + 6b = 3 [/3

3a + 2b = 1 [*5

15a + 10b = 5

25a + 35b = 5 [/5

5a + 7b = 1 [*3

15a + 21b = 3

Now they both have 15a in them, we can take one from the other

15a + 21b = 3

- 15a + 10b = 5

----------------------

11b = -2

b = -2/11

Now find what a is by substituting in the value of b:

9a + 6b = 3

9a = 3 - 6b

a = (1 - 2b) / 3 , b = -2/11

a = (1 - 2(-2/11))/3

a = (1+4/11)/3 = (15/11)/3 = 5/11

a = 5/11

To check our anwsers, substitute in the values for a and b

9a + 6b = 3

9*5/11 + 6*-2/11 = 3, good

25a + 35b = 5

25*5/11 + 35*-2/11 = 5, good

all correct. so the solutions are:

a = 5/11

b = -2/11

Hopes this helps!!

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What is the value of 9a + 6b?​

What is the value of 9a + 6b?