Question

If 2a + 3b + 4c = 35, 3a + 5b + 7c = 30 then a + b + c =?

Answer 1

Answer:

Your answer is 40.

Step-by-step explanation:

2a + 3b + 4c = 35

3a + 5b + 7c = 30

Starting with the second given equation;

3a + 5b + 7c = 30

(2a + 3b + 4c) + (a + 2b + 3c) = 30

35 + (a + 2b + 3c) = 30        

a + 2b + 3c = -5______(1)

Now, using the first equation

2a + 3b + 4c = 35

( a + 2b + 3c) + (a + b + c)=35

-5 +(a + b + c)=35 [ using__(1)]

a + b +c = 40