Question

Add 5a-3b +4c and -8a+7b+9c.

Answer 1

Answer:

First we find the sum of (a + 3b – 4c), (4a – b + 9c) and (-2b + 3c – a)

= (a + 3b – 4c) + (4a – b + 9c) + (-2b + 3c – a)

= (a + 3b – 4c + 4a – b + 9c – 2b + 3c – a)

= (a + 4a – a) + (3b – b – 2b) + (-4c + 9c + 3c)

= (1 + 4 – 1)a + (3 – 1 – 2)b + (-4 + 9 + 3)c

= 4a + (0)b + 8c

=4a + 8c

Then,

Subtract (2a – 3b + 4c) from (4a + 8c)

= (4a + 8c) – (2a – 3b + 4c)

= 4a + 8c – 2a + 3b – 4c

= (4a – 2a) + (3b) + (8c – 4c)

= 2a + 3b + 4c

Answer 2

Answer:

-3 a +4 b+13 c

5a -3b +4c

+-8a +7b +9c

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-3 a +4 b+13 c

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