# If a + 7b + 4c = 2. what is 36c + 9a + 63b?

Nov 24, 2016

I got $18$
$36 c + 9 a + 63 b =$ collecting $9$:
$= 9 \cdot \left(4 c + a + 7 b\right)$
so it is $4$ times the given $a + 7 b + 4 c$ which in the definition is equal to $2$; so:
$= 9 \cdot \left(4 c + a + 7 b\right) = 9 \cdot 2 = 18$